TEST BANK for Microbiology Basic and Clinical Principles 1st Edition Lourdes P. Norman-McKay by ACADEMIAMILL

Exam Name

Chapter 1

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following is not a microorganism? A) mosquito B) helminth C) archaea

1) D) bacteria

E) fungi

2) When do opportunistic pathogens tend to cause disease? A) when the host didn't wash with soap B) when the host is weakened C) when the host is young D) after the host is already infected with a different pathogen E) when the host is old

3) Which of the following could be used as evidence for spontaneous generation? A) The broth in Pasteur's S-necked flasks did not spoil. B) Flies lay eggs that develop into maggots. C) Gauze-covered meat will not give rise to maggots. D) Uncovered meat will give rise to maggots. E) Shaking Pasteur's S-necked flasks did spoil the broth.

showed that biogenesis is responsible for the propagation of life. A) Robert Hooke B) Joseph Lister C) Antonie van Leeuwenhoek D) Louis Pasteur E) Carl Linnaeus

5) Robert Koch helped establish the germ theory of disease by discovering that anthrax was caused by a disease. After he isolated and purified the same bacteria from several diseased animals, what would be the next step in order to show that this bacteria caused anthrax? A) perform physiological testing B) visualize the bacteria with an electron microscope C) introduce the bacteria into a new mouse to see if it established the same infection D) find out if antibiotics treat the diseased animals E) culture the bacteria on Petri dishes

6) How many principles are there in Koch's postulates of disease? A) 1 B) 2 C) 3 D) 4

7) Aseptic technique can be used for all of the following except A) preventing healthcare-acquired infections. B) sterilizing working surfaces. C) limiting the spread of diseases. D) keeping samples pure for studying. E) safely studying microbes in the laboratory.

E) 5 7)

8) Which of the following individuals does not correctly match with their contribution to microbiology. A) Robert Koch: Developed criteria for determining the causative agent of an infectious disease B) Ignaz Semmelweis: First developed aseptic techniques to decrease mortality rates from childbed fever C) Florence Nightingale: Established the use of aseptic techniques in nursing practices D) Louis Pasteur: Showed that biogenesis is responsible for the propagation of life E) Joseph Lister: Developed the first anesthetic solution for use in surgeries

9) The scientific method starts with a(n) A) proposal. B) hypothesis. C) observation. D) question. E) prediction.

10) Inference-observation confusion occurs when someone A) lies about what happened. B) jumps to a conclusion. C) incorrectly assesses a patient. D) cannot understand your accent. E) remembers events wrong.

10)

11)

predict what happens, while A) Laws; theories B) Hypotheses; conclusions C) Observations; conclusions D) Observations; hypotheses E) Theories; laws

explain how and why something occurs.

12) Which of the following is the correct way to type a scientific name? A) escherichia coli B) Escherichia Coli C) Escherichia coli D) escherichia coli E) Escherichia coli

12)

13) What is the order of the taxonomic hierarchy from least specific to most specific? A) domain, order, class, kingdom, phylum, species, family, genus B) species, genus, order, family, class, phylum, kingdom, domain C) class, order, phylum, kingdom, domain, genus, family, species D) domain, phylum, order, kingdom, class, family, genus, species E) domain, kingdom, phylum, class, order, family, genus, species

13)

14) All of the following are reasons to classify a new strain of bacteria except A) take up genetic material from their environment. B) mutations. C) gene transfers. D) genetic variant. E) 50% different genetic material.

14)

15) Why can't prokaryotic species be defined as a group of similar organisms that could sexually reproduce together? A) The mating rituals of bacteria have not been studied enough. B) Bacteria reproduce asexually. C) Bacteria are all too different to be considered similar. D) We can't see them in enough detail to tell how similar they really are yet. E) They can be.

15)

16) Normal microbiota are responsible for all of the following except A) controlling epigenetic expression. B) producing vitamins for us. C) training our immune system. D) impacting our moods and brain functions. E) helping us digest foods.

16)

17) Which of the following does not contribute to shifts in our normal microbiota? A) our general environment B) hormonal changes C) proper hand-washing technique D) diet E) age

17)

18) Microbes and humans have evolved a variety of microbes help the host. A) symbiotic; parasitism B) dynamic; commensalism C) symbiotic; commensalism D) symbiotic; mutualism E) commensal; mutualism

relationships, including

where

18)

19) Carriers of the sickle-cell gene A) are often found in high concentrations in U.S. cities. B) have a survival advantage in areas where malaria is common. C) experience painful changes in nerve cell shape. D) are more susceptible to contracting malaria. E) are more likely to die from a malaria infection.

19)

20) Which of the following is true about bioremediation? A) The Environmental Protection Agency documents a handful of chemical spills per year in the United States alone. B) Coagulators are used to condense the spill. C) Nitrogen, sulfur, phosphate, and sometimes iron supplements are added to the spill zone to encourage microbial growth. D) A mix of bacteria, archaea, and fungi species is used to seed the spill zone. E) Bioremediation never harms the environment.

20)

21) All of the following are or can be produced by microbes except A) food like chocolate. B) drugs like penicillin. C) electronics like computer memory. D) consumer products like biodegradable plastics. E) biofuels like diesel.

21)

22) All of the following involve biofilms except A) atherosclerosis. B) endocarditis. C) kidney stones. D) conjunctivitis. E) inner ear infections.

22)

23)

bacteria can create sticky communities called diverse microbial species. A) Planktonic; biofilms B) Plaque; hangouts C) Matrix; cavities D) Pathogenic; quorums E) Infectious; flora

, which are made up of single or

23)

24) Which of the following statements is true? A) Agar is used as a solidifying agent for bacterial culture. B) Media for bacterial growth only comes in a few varieties. C) Picking which type of media format to use depends only on the space available. D) Scientists were not able to grow bacteria in the lab until the creation of the Petri dish. E) Picking which type of media to use depends on how much money you willing to spend.

24)

25) When practicing aseptic culturing techniques, it is important to keep all of the following in mind except A) all of the instruments and lab ware that directly touch the specimen is sterile. B) as long as nothing unintended touches the media, there will be no contamination. C) gloves and other protecting clothing may be required depending on the specimen being used. D) surrounding surfaces are decontaminated before and after handling cultures. E) the media used to grow the specimen is sterile.

25)

26) A biological safety cabinet minimizes the chances of contaminating cultures by all of the following except A) maintaining a specific flow of filtered air. B) consistent flame sterilization on the inside surfaces. C) readily being decontaminated using UV light. D) limiting access to inside the cabinet. E) regular surface cleaning with an antimicrobial solution.

26)

27) The goal of the streak plate technique is to A) compare how the shape, color and margin differ in colonies from a pure culture. B) compare all of the colonies on a plate with a mixed culture. C) visualize all of the colonies on a plate from a pure culture. D) isolate a pure culture for study from a single colony. E) spread out a thick layer of bacteria and isolate the bacteria that outcompete the rest.

27)

28) Which of the following can be determined using simple stains? A) the number and position of flagella B) size and shape C) size, shape and cellular arrangement D) the presence of capsules E) the presence of endospores

28)

29) All of the following can make interpreting the Gram stain difficult except A) the culture is more than 48 hours old and contains damaged cells. B) the culture is between 24 and 48 hours old. C) testing bacteria with especially resistant cell walls. D) testing bacteria that have a waxy cell wall. E) testing bacteria that are forming endospores.

29)

30) The acid-fast stain is an important diagnostic tool for detecting the causative agent(s) of A) tuberculosis and leprosy. B) malaria. C) gonorrhea. D) plague. E) Lyme disease and necrotizing fasciitis.

30)

31) Which of the following statements is true about the decolorizing step for the acid-fast stain? A) Non-acid-fast bacteria appear bright pink-red at the end of the procedure. B) Over-decolorizing can lead to false-positive results. C) Because acid-fast bacteria have a waxy cell wall that resists decolorization by the acetone-alcohol rinse, they appear a deep blue at the end of the procedure. D) The decolorizing step is the differentiating step. E) Acetone-alcohol solution is the decolorizing agent.

31)

32) Which of the following statements about bright field microscopy are true? A) Bright field microscopy is great for seeing living samples. B) Bright field microscopy has the sample appear as a brighter contrasting image on a dark background. C) Bright field microscopy is able to see specimens without natural coloration. D) Bright field microscopy is the simplest and most common form of microscopy. E) Dark field, phase contract, and differential interference contract microscopy are better for observing dead samples.

32)

33) Which of the following statements is false? A) Ultimately, the resolving power of bright field microscopes is limited by the wavelength of visible light. B) Immersion oil channels as much light as possible up through the objective lens instead of being bent. C) Immersion oil is used to get a better resolution at high-power magnifications. D) Immersion oil has a lower refractive index than the glass slide to help increase sample clarity. E) Resolution is the ability to distinguish two distinct points as separate.

33)

34) Which of the following statements is false? A) Fluorescence microscopy is when fluorochromes stain a sample so it will fluoresce when exposed to UV light. B) Fluorochromes can be natural or synthetic. C) Immunofluorescence is when fluorochromes bind to a specific target and fluoresce after exposure to UV light. D) Scanning electron microscopy provides information about surface structures. E) Transmission electron microscopy provides information about internal structures.

34)

35) Why do electron microscopes have a better resolution versus light microscopes? A) An electron beam has a wavelength of about 800 nm, and resolution improves with larger wavelengths. B) An electron beam has a wavelength of about 1 nm, and resolution improves with smaller wavelengths. C) The lenses used to focus the electron beam are more adjustable than the ones in a light microscope. D) The additional steps necessary to prepare the sample for viewing provide the improved resolution. E) The lenses, knobs, and strength of the electron beam can all be highly controlled, which also explains why electron microscopes are so expensive.

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) Robert Hooke refined earlier versions of the microscope and became the first to see bacteria.

36)

37) Florence Nightingale investigated processes for aseptic surgery and her work in the 1860s proved that sterilizing instruments, and sanitizing wounds with carbolic acid encouraged healing and prevented pus formation.

37)

38) Only a small minority of microbes are human pathogens.

38)

39) Proper hand-washing technique can remove normal microbiota.

39)

40) Biofilms allow microbes to coordinate responses within an environment, making the community much more durable than single free-floating bacteria.

40)

41) Fixation adheres the sample to the slide, so that it is not as easily washed away during the staining process, but does not kill most of the cells in the specimen so that they can be clearly viewed.

41)

42) Simple staining techniques use one dye.

42)

43) Knowing the Gram property of a specimen has important clinical implications, including potential pathogenic features of the organism, and what antibiotics might be most effective in combating it.

43)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 44) Explain the differences between a hypothesis, law, and theory. 45) Explain how disruptions in normal microbiota can lead to infections.

46) Explain the differences between basic and acidic dyes and how they are used.

Answer Key Testname: UNTITLED15

1) A 2) B 3) D 4) D 5) C 6) D 7) B 8) E 9) D 10) B 11) A 12) E 13) E 14) E 15) B 16) A 17) C 18) D 19) B 20) C 21) C 22) D 23) A 24) A 25) B 26) B 27) D 28) C 29) B 30) A 31) D 32) D 33) D 34) C 35) B 36) FALSE 37) FALSE 38) TRUE 39) FALSE 40) TRUE 41) FALSE 42) TRUE 43) TRUE 44) A hypothesis is based on prior experience or observation, and is proposed as a potential answer to a specific question. A law is a precise statement, or mathematical formula, that predicts a specific occurrence. Laws only hold true under carefully defined and limited circumstances. By contrast, a theory is a hypothesis that has been proven through many studies with consistent, supporting conclusions. Laws predict what happens, while theories explain how and why something occurs. Unlike a hypothesis, which focuses on a specific problem, theories are comprehensive bodies of work that are useful for making generalized predictions about natural phenomena. Theories unite many different hypotheses and laws. 8

Answer Key Testname: UNTITLED15

45) When an antibiotic is used, it may kill many types of benign resident bacteria along with the pathogen being targeted. With normal microbiota reduced, opportunistic pathogens are able to establish infections. A common example of this is when a woman takes antibiotics to treat a urinary tract infection (UTI), only to develop a vaginal yeast infection soon after the antibiotic therapy concludes. The yeast Candida albicans is an opportunistic pathogen that is usually present in the vagina. Its growth is kept in check by the normal microbiota of the vagina. Thus, when the vaginal normal microbiota is disrupted, the yeast has an opportunity to thrive and cause symptoms. Similarly, diarrhea is a common side effect of antibiotic therapies, likely due to how our gut microbiome is affected. 46) Basic dyes are mildly basic on the pH scale. Being basic means they are positively charged, resulting in the stain being attracted to the negatively charged cell surface of microbes and easily entering cells. Frequently used basic dyes include methylene blue, crystal violet, safranin, and malachite green. Occasionally acidic dyes, such as nigrosin or India ink, are also used. Acidic dyes are negatively charged, so they do not easily enter cells. They stain the background of a specimen in a technique called negative staining. An advantage of negative staining is that it doesn't require heating or chemical fixation, and the dye is not absorbed by the sample. This means the sample has a more true-to-life appearance, with fewer distortions of delicate cellular features.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) An atom is best described as A) defined by its atomic mass. B) always containing an equal number of protons and neutrons. C) defined by its number of electrons. D) having a nucleus containing protons and electrons. E) the smallest unit of an element.

2) Which particle is described incorrectly? A) Electron: Negatively charged and negligible mass B) Proton: Found in shells orbiting the nucleus C) Neutron: Found in the nucleus and 1 atomic mass unit D) Proton: Positively charged and 1 atomic mass unit E) Electron: Found in shells orbiting the nucleus

3) What information can you determine about the element nitrogen from the periodic table entry show

A) The atomic number for nitrogen is 14.007 and there are 14 neutrons in the nucleus of a nitrogen atom. B) The atomic number for nitrogen is 14.007. C) There are 14 neutrons in the nucleus of a nitrogen atom. D) The atomic number for nitrogen is 7. E) The atomic number for nitrogen is 7 and there are 14 neutrons in the nucleus of a nitrogen atom.

4) An anion is formed when A) an atom has an equal number of positively-charged protons and negatively-charged electrons. B) an atom gains one or more negatively-charged electrons. C) an atom loses one or more positively-charged protons. D) an atom loses one or more negatively-charged electrons. E) an atom gains one or more positively-charged protons.

5) Isotopes are atoms of the same element that differ in A) the number of protons found in the nucleus. B) the number of protons and neutrons found in the nucleus. C) the number of neutrons found in the nucleus. D) the number of protons and electrons found in the atom. E) the number of electrons orbiting the nucleus.

6) A feature of many of the isotopes that are used in the field of medicine is that the isotopes are radioactive. What does this mean? A) Cationic forms of the atom are used. B) The same number of atoms are arranged into different molecular structures. C) The nucleus of the isotope is unstable and breaks down over time. D) Anionic forms of the atoms are used. E) The atoms with the greatest atomic mass are used.

7) The pictured molecules both contain six carbon atoms, twelve hydrogen atoms, and six oxygen atoms (C6H12O6). However, these atoms are arranged differently in each molecule. What are these

molecules called?

A) anions B) functional groups C) isomers D) R groups E) isotopes

8) Which of the following is an organic compound? A) ethanol (C2H6O) B) ethanol (C2H6O) and methane (CH4) C) carbon dioxide (CO2) D) carbon dioxide (CO2), ethanol (C2H6O), and methane (CH4) E) methane (CH4) 9) Which functional group is incorrectly matched with its structure? A) alcohol: R-OH B) phosphate: R-PO42-

C) ether: R-CH3 D) carboxyl: R-COOH E) amino: R-NH2 10) Which of the following is incorrectly matched? A) Base: Release hydroxide ions (OH-) in an aqueous solution

10)

B) Acid: Release hydrogen ions (H+) in an aqueous solution C) Salt: Formed by the combination of hydrogen ions (H+) and hydroxide ions (OH-) D) pH: Measure of the acidity or basicity of a solution E) Water: Is the solvent in aqueous solutions 11)

11) Pure water is defined by A) a neutral pH of 7. B) a neutral pH of 7, and equal number of H+ and OH- ions, and its ability to serve as a pH buffer in solutions. C) its ability to serve as a pH buffer in solutions. D) a neutral pH of 7 and an equal number of H+ and OH- ions. E) an equal number of H+ and OH- ions. 12) Compared to a solution with a pH value of 4, a solution with a pH value of 2 has A) twice as many B) the same number of C) one hundred times as many D) one hundred times fewer E) half as many 13) A compound which stabilizes pH by absorbing or releasing H+ ions is called a(n) A) salt. B) solute. C) base. D) acid.

H+ ions.

13) E) buffer.

14) Which statement is true about valence electrons? A) Interactions between valence electrons in reacting atoms determine what kind of chemical bond is formed. B) Valence electrons participate in chemical reactions. C) Valence electrons participate in chemical reactions, and interactions between valence electrons in reacting atoms determine what kind of chemical bond is formed. D) Valence electrons are found in the innermost shell. E) Valence electrons are found in the innermost shell and participate in chemical reactions.

12)

14)

15) Ionic bonds A) form when electrons are transferred from atom to another and only exist as ions in solution. B) only exist as ions in solution. C) are electrostatic forces of attraction between oppositely charged ions. D) form when electrons are transferred from atom to another. E) are electrostatic forces of attraction between oppositely charged ions and form when electrons are transferred from atom to another.

15)

16) Which of the following shows an ionic bond? A)

16)

17) Electrolytes A) include acids, bases, and salts, are ionic compounds dissolved in solution and are involved in regulating the nervous system, heartbeat, blood volume and water balance in the body. B) are involved in regulating the nervous system, heartbeat, blood volume and water balance in the body. C) are ionic compounds dissolved in solution. D) are ionic compounds dissolved in solution and are involved in regulating the nervous system, heartbeat, blood volume and water balance in the body. E) include acids, bases, and salts.

17)

18) In a polar covalent bond, A) electrons are shared equally between two atoms. B) electrons are shared unequally between more than two atoms. C) electrons are shared unequally between two atoms. D) an acid and a base neutralize each other to form a salt. E) electrons are transferred from one atom to another.

18)

19) In the figure shown, which atom(s) will have a partial negative charge?

A) nitrogen and oxygen B) nitrogen C) oxygen D) hydrogen and oxygen E) hydrogen

19)

20) In the figure shown, what does the dotted line represent?

20)

A) an interaction between a hydrophilic and a hydrophobic molecule B) sharing of electrons between the ammonia and water molecules C) transfer of the electron from the hydrogen atom to the nitrogen atom D) an electrostatic interaction between the partially-positive hydrogen and the partially-negative nitrogen E) a Van der Waals interaction 21) Hydrogen bonds A) are involved in stabilizing the structure of proteins and nucleic acids and form whenever hydrogen is involved in any covalent or ionic bond. B) are responsible for the unique properties of water and are involved in stabilizing the structure of proteins and nucleic acids. C) are involved in stabilizing the structure of proteins and nucleic acids. D) are responsible for the unique properties of water. E) form whenever hydrogen is involved in any covalent or ionic bond.

21)

22) Van der Waals interactions A) are stronger than either hydrogen bonds or ionic bonds. B) are responsible for the repulsion between hydrophilic and hydrophobic compounds. C) exhibit a force of repulsion that serves to destabilize molecules. D) occur when temporary dipoles within molecules form that are not the result of hydrogen bond to O, N, or F atoms. E) are another name for hydrogen bonds.

22)

23) Which term is incorrectly matched to its description? A) Hydrophilic: Substances which readily dissolve in water AND hydrophobic: substances which are not readily dissolved in water are both incorrectly matched. B) Amphipathic: Has properties that are neither hydrophilic nor hydrophobic C) Hydrophilic: Substances which readily dissolve in water D) Amphipathic: Has properties that are neither hydrophilic nor hydrophobic; hydrophilic: substances which readily dissolve in water; AND hydrophobic: substances which are not readily dissolved in water are all incorrectly matched E) Hydrophobic: Substances which are not readily dissolved in water

23)

24) A micelle is formed of A) amphipathic molecules where the hydrophilic portion faces toward the center. B) both hydrophilic and hydrophobic molecules. C) hydrophobic molecules only. D) amphipathic molecules where the hydrophobic portion faces toward the center. E) hydrophilic molecules only.

24)

25) Plasma membranes, the key boundary layer of cells, are composed of amphipathic molecules called phospholipids. Why would neither purely hydrophilic nor purely hydrophobic molecules be a suitable molecule for plasma membranes? A) Hydrophilic molecules would dissolve in the aqueous environment in which cells live, disrupting the structural integrity of the cell, and hydrophobic molecules would be unable to interact with the aqueous environment in which cells live. B) Hydrophobic molecules would be unable to interact with the aqueous environment in which cells live. C) Both hydrophilic and hydrophobic molecules would dissolve in the aqueous environment in which cells live, disrupting the structural integrity of the cell. D) Hydrophobic molecules would dissolve in the aqueous environment in which cells live, disrupting the structural integrity of the cell, while hydrophilic molecules could not interact. E) Hydrophilic molecules would dissolve in the aqueous environment in which cells live, disrupting the structural integrity of the cell.

25)

26) Consider the reaction AB → A + B. What is the product of this reaction? A) A B) B C) AB D) A and B E) A, B, and AB

26)

27) Which reaction has X and Y as reactants?

27)

A) XY → X + Y B) XY + AB → XB + AY C) XY + W → WY + X D) X + YZ → Y + XZ E) X + Y → XY 28) Which statement does not describe a catalyst? A) A catalyst may be an inorganic substance. B) A catalyst is not used up in the reaction. C) A catalyst may be an organic substance. D) A catalyst will increase the rate of a reaction. E) A catalyst will decrease the rate of a reaction.

28)

29) Which reaction is incorrectly matched with its name?

29)

A) Single exchange: AB + C → AC + B B) Decomposition: AB → A + B C) Hydrolysis: A + B → AB + H2O D) Synthesis: A + B → AB E) Double exchange: AB + CD → AD + CB 30) In a dehydration synthesis reaction, macromolecules are built when covalent bond. A) carbon dioxide B) an electron C) oxygen D) water E) an amino acid

is removed to form a

30)

31) What type of reaction does the figure show?

31)

A) decomposition B) dehydration synthesis and hydrolysis C) hydrolysis D) decomposition and hydrolysis E) dehydration synthesis 32) Activation energy A) is the minimum amount of energy needed to get a reaction started and is due to the necessity of collisions between reactants which have enough energy and with the reactants properly oriented. B) is the minimum amount of energy needed to get a reaction started. C) is due to the necessity of collisions between reactants which have enough energy and with the reactants properly oriented. D) can be lowered by catalysts such as enzymes in biochemical reactions. E) is the minimum amount of energy needed to get a reaction started and is due to the necessity of collisions between reactants which have enough energy and with the reactants properly oriented and can be lowered by catalysts such as enzymes in biochemical reactions.

32)

33) The figure shown is an exergonic reaction because

33)

A) it is a decomposition reaction and the products have a lower final energy than the reactants. B) it is a decomposition reaction. C) activation energy was required and the products have a lower final energy than the reactants. D) the products have a lower final energy than the reactants. E) activation energy was required. 34) Which of the following does not describe equilibrium? A) when there is an equal amount of products and reactants and a reaction has stopped B) A forward and reverse reaction occur at the same rate. C) The total amount of products and reactants is no longer changing. D) A reaction has stopped. E) when there is an equal amount of products and reactants

34)

35) Which of the following is not one of the four main groups of biomolecules? A) lipids B) proteins C) nucleic acids D) electrolytes E) carbohydrates

35)

36) Which of the biomolecules is incorrectly matched with its building block? A) Nucleic acid: Nucleotide B) Carbohydrate: Polysaccharide C) Lipid: Fatty acid D) Protein: Amino acid E) Lipid: Glycerol

36)

37) The type of bond which links the amino group of one amino acid to the carboxyl group of another amino acid is called a(n) A) peptide bond. B) phosphodiester bond. C) glycerol bond. D) glycosidic bond. E) amino bond.

37)

38) Which statement is true about carbohydrates? A) They are usually hydrophobic. B) They are a component of the cell wall of different types of organisms. C) They maybe saturated or unsaturated. D) They consist of simple sugars which contain carbon, hydrogen, and oxygen in a 2: 1: 2 ratio. E) They have primary, secondary, tertiary, and quaternary structure.

38)

39) Which type of lipid is incorrectly matched to its description? A) Mono-, di-, or triglyceride: One, two, or three fatty acids linked to a glycerol molecule B) Wax: Refers to any lipid which is solid at room temperature C) Glycolipid: A lipid linked to a carbohydrate D) Steroid: Made of four fused hydrocarbon rings E) Phospholipid: An amphipathic lipid found in the plasma membrane of cells

39)

40) Deoxyribonucleotides and ribonucleotides differ in all of the following except A) the nitrogenous base thymine is only found in deoxyribonucleotides while the nitrogenous base uracil is only found in ribonucleotides. B) the sugar is different in the two types of nucleotides. C) phosphodiester bonds can only form between deoxyribonucleotides, not ribonucleotides. D) deoxyribonucleotides are found in DNA while ribonucleotides are found in RNA. E) ribonucleotides can serve as energy molecules while deoxyribonucleotides do not.

40)

41) Plasma membranes must be in a fluid (liquid) state in order to function properly. Fluidity is temperature-dependent. Bacteria can regulate the specific lipid composition of their plasma membranes. Which of the following statements is true? A) The proportion of saturated lipids in the plasma membrane will increase with both cooler and warmer growth temperatures. B) The proportion of unsaturated lipids in the plasma membrane will increase with cooler growth temperatures. C) The proportion of saturated lipids in the plasma membrane will increase with cooler growth temperatures while the proportion of unsaturated lipids will increase with warmer growth temperatures. D) The proportion of unsaturated lipids in the plasma membrane will increase with warmer growth temperatures. E) The proportion of saturated lipids in the plasma membrane will increase with cooler growth temperatures.

41)

42) The primary structure of a protein A) is the linear sequence of amino acids which are held together by peptide bonds and is dictated by genetic sequence and is unique to that protein and lays the foundation for all higher order structure of that protein. B) is the linear sequence of amino acids which are held together by peptide bonds. C) is the linear sequence of amino acids which are held together by peptide bonds and is dictated by genetic sequence. D) is dictated by a genetic sequence. E) is unique to that protein and lays the foundation for all higher order structure of that protein.

42)

43) Which level of protein structure can involve hydrogen bonds? A) primary B) secondary C) tertiary D) primary and secondary E) secondary and tertiary

43)

44) In the human genetic disease sickle cell anemia, a single change in the genetic sequence of the hemoglobin-beta gene results in the amino acid valine being substituted for the amino acid glutamic acid in the beta chain of the hemoglobin protein. Which level(s) of the protein structure will be affected? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure E) primary, secondary, tertiary, and quaternary structures

44)

45) Chaperone proteins A) escort proteins to the location in a cell where they are needed. B) ensure that a protein is folded correctly. C) ensure that DNA molecules form double-stranded helices. D) cleave a phosphate from ATP to release energy. E) ensure that amino acids are placed in the correct order when forming a protein.

45)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 46) A cation forms when an atom loses one or more negatively-charged electrons.

46)

47) Water (H2O) and carbon dioxide (CO2) are both molecules and compounds.

47)

48) A molecule of glucose contains six carbon atoms, twelve hydrogen atoms, and six oxygen atoms. The proper way to write the molecular formula for glucose is 6C12H6O.

48)

49) Acids increase the H+ concentration in a solution and so lower pH.

49)

50) Blood pH is stabilized by carbonic acid (H2CO3) which releases H+ ions to lower pH and bicarbonate (HCO3-) which absorbs H+ ions to raise pH.

50)

51) During vigorous exercise, both carbon dioxide and lactic acid enter the blood in increased amounts. Both compounds have the effect of lowering the blood pH. In order to maintain blood pH within the normal range of 7.35-7.45, we would expect the carbonic acid (H 2CO3) portion of the blood buffer system to pick up the extra H+ ions.

51)

52) In a polar covalent bond involving hydrogen and oxygen, the hydrogen takes on a partial negative charge while the oxygen takes on a partial positive charge.

52)

53) Endergonic reactions make products with a lower final energy than the reactants and use more energy than is released.

53)

54) A reversible reaction is one in which the forward and reversible reactions are both possible such as: AB → A + B and A + B → AB.

54)

55) A phosphodiester bond links a fatty acid to a glycerol molecule to form a fat or an oil.

55)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 56) Describe the relationship between acids, bases, salts, and water, and explain how the pH scale is used to measure acidity and basicity. 57) Compare and contrast ionic bonds, covalent bonds, polar covalent bonds, and hydrogen bonds. Explain how valence electrons are involved in the formation of each. 58) Vitamin deficiencies (not getting enough of a certain vitamin) pose obvious health problems, but an excess of certain vitamins in the system can also be harmful. Explain why you would be far less likely to experience an excess of water-soluble vitamins compared to fat-soluble vitamins in the context of the characteristics of polar and nonpolar substances. 59) List the four types of biomolecules. For each type, name the monomer building block, the type of chemical bond which joins the building block, and give two functions, naming a specific example where appropriate. 60) List and describe the four levels of protein structure. Explain how the levels of structure are dependent on each other and describe what types of molecular interactions are involved.

Answer Key Testname: UNTITLED16

1) E 2) B 3) D 4) B 5) C 6) C 7) C 8) B 9) C 10) C 11) D 12) C 13) E 14) C 15) E 16) C 17) A 18) C 19) A 20) D 21) B 22) D 23) B 24) D 25) A 26) D 27) E 28) E 29) C 30) D 31) D 32) E 33) D 34) A 35) D 36) B 37) A 38) B 39) B 40) C 41) B 42) A 43) E 44) E 45) B 46) TRUE 47) TRUE 48) FALSE 49) TRUE 50) TRUE 15

Answer Key Testname: UNTITLED16

51) FALSE 52) FALSE 53) FALSE 54) TRUE 55) FALSE 56) Acids are substances that increase the concentration of hydrogen ions (H +) when dissolved in water. Bases are substances that increase the concentration of hydroxide ions (OH-) when dissolved in water. When an acid and a base are mixed, the result is a salt and water. For example: hydrogen chloride + sodium hydroxide → sodium chloride and water or HCl + NaOH→ NaCl + H2O. The pH scale measures the amount of H+ ions in an aqueous solution. Neutral pH is defined as 7.0 where the amount of H+ ions and OH- ions are equal; this is the pH of pure water. Acids lower pH values; values below 7 are considered acidic and lower numbers are more acidic than higher numbers. Bases raise pH value; values above 7 are considered basic and higher numbers are more basic than lower numbers. The pH scale is a logarithmic scale, so each whole number step pH represents a tenfold change in acidity or basicity. 57) Chemical bonds form between two atoms to form molecules. Chemical bonds form by the action of the valence electron found in the outer shell of each atom. Atoms combine in a way to achieve full valence shells which is the most stable configuration for atoms. Ionic bonds are electrostatic forces of attraction between a cation and an anion. These bonds form when one or more val electrons are transferred from one atom to another. The receiving atom becomes the negatively-charged anion while the donating atom becomes the positively-charged cation. Covalent bonds are electrostatic forces of attraction between atoms that share one or more pairs of valence electrons. The two atoms may share the paired electrons equally or symmetrically in which case the covalent bond is referred to as nonpolar. Conversely, the shared valence electron pair may spend more time orbiting one of the atoms in the pair than the other. This causes the first atom to acquire a partial negative charge while the other acquires a partial positive charge. In this case, the covalent bond is said to be polar. Hydrogen bonds are not really bonds but are noncovalent electrostatic interactions between atoms in two different molecules or within the same, large molecules. Hydrogen bonds form because of the partial negative or positive charges that occur on polar molecules. In particular, when hydrogen is bonded to either oxygen or nitrogen, the hydrogen becomes partially-positively charged, while the oxygen or nitrogen is becomes partially-negatively charged. The attraction of the oppositely charged atoms forms the hydrogen bond. 58) Water-soluble vitamins are polar molecules which dissolve in water (hydrophilic). They are easily excreted from the body in the urine, and therefore are unlikely to build up to toxic levels. Fat-soluble vitamins are non-polar. They do not dissolve in water (hydrophobic) and so are not easily excreted in urine. Instead they are stored in fat, where it is possible for them to build up to unsafe levels if an excess amount is ingested over a period of time.

Answer Key Testname: UNTITLED16

59) The four types of biomolecules are carbohydrates, lipids, nucleic acids, and proteins. (1) Carbohydrates include monomer building blocks called monosaccharides, or simple sugars which usually have 3, 5, carbons along with hydrogen and oxygen in a 1: 2: 1 ratio. A monosaccharide may join with another monosaccharide th glycosidic bond to form a disaccharide; multiple monosaccharides chained together through glycosidic bonds are called polysaccharides. Carbohydrates are the chief energy sources in biological systems, serve as structural biomolecules, and mediate cellular adhesion, communication, and environmental sensing. Glucose is a favorite energy source for cells while cellulose, peptidoglycan, and chitin are all constituents of cell walls. (2) Lipids are a group of mostly hydrophobic molecules including fats, oils, waxes, and steroids. Lipids such as fats and oils are composed of fatty acid chains attached to a glycerol molecule through an ester bond. The fatty acids may be saturated (no double bonds, i.e. the maximum possible amount of hydrogen is bonded to each carbon atom) or unsaturated (one or more double bonds, i.e. less than the maximum number of hydrogen atoms bonded to each carbon atom). Fats and oils serve as energy sources for cells, as cell structure components, and mediate cell signaling. Waxes are fatty acids bonded to a long-chain alcohol; they serve a variety of protective functions. Steroids are composed of four fused hydrocarbon rings; they are involved in cell signaling pathways. (3) Nucleic acids come in two varieties: DNA and RNA. Both are composed of polymers of nucleotide monomers. Nucleotides are held together in chains through a phosphodiester bond. Each nucleotide is composed of a pentose sugar (deoxyribose or ribose), 1 -3 phosphate groups, and one of five nitrogenous bases. DNA serves as the genetic blueprint for all cells and some viruses; RNA can serve as the genetic blueprint for viruses and directs the production of proteins in all cells and viruses. (4) Proteins are polymers of amino acids joined in a chain by peptide bonds. The sequence of amino acids used in a given protein is unique to that protein and determines the structural and functional characteristics of that protein. Proteins typically fold into specific three-dimensional structures which are determined by the amino acids found in the protein. Proteins may serve as structural scaffolds in cells, as enzymes facilitating chemical reactions, cellular transporters, and are involved in cell recognition and communication. 60) The four levels of protein structure include primary, secondary, tertiary, and quaternary structure. (1) Primary structure is the linear sequence of amino acids in the protein, which are linked together by a type of covalent bond known as a peptide bond. A protein's primary structure is unique to that type of protein, and the overall structure and function of the protein results from the properties of each amino acid in the protein. All higher levels of protein structure are dependent on specific interactions between particular amino acids, so the primary structure of a protein determines its secondary, tertiary, and (if applicable) its quaternary structure. (2) Secondary structure consists of regular, consistent coils or folds in the protein chain which are held together by hydrogen bonds between amino acids. Types of secondary structure include alpha-helices and beta-pleated sheets. (3) Tertiary structure is the folding of the protein chain upon itself to form a characteristic three-dimensional structure. These structures are formed by both covalent and noncovalent interactions between specific amino acids. Not all proteins display quaternary structure. (4) Quaternary structure occurs when two or more separate polypeptide chains combine to form a functional protein. Both noncovalent and covalent interactions are involved in quaternary structure.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following statements is false? A) Prokaryotes are unicellular and lack a membrane-bound nucleus. B) Eukaryotes have a much simpler genetic makeup than prokaryotic cells. C) Eukarya is a eukaryotic domain. D) Eukaryotic cells evolved from prokaryotic cells. E) Archaea and Bacteria are prokaryotic domains.

2) Why aren't Archaea discussed as much as bacteria? A) Archaea infections are easy to treat. B) Archaea are not part of the human microbiome. C) Archaea haven't been linked to human diseases. D) Archaea are only found in a few limited environments. E) Archaea only live in extreme environments.

3) Why are most prokaryotic cells small? A) Intracellular inclusions demand that cell size be small. B) Storage bodies within a cell enable cells to be small so they need less nutrients. C) Nutrient diffusion is most efficient for smaller cells. D) A high surface area-to-volume ratio helps smaller cells divide easier. E) A low surface area-to-volume ratio helps smaller cells divide easier.

4) Which of the following cell shapes look like a comma? A) vibrio B) spirochetes C) bacilli D) coccobacilli E) stella

5) Cell shape is determined by which of the following? A) whether or not the species uses a flagellum B) the way cells divide C) whether or not the species is pathogenic D) cell wall and cytoskeleton components E) the way cells move through their media

6) Which of the following arrangements is sometimes referred to as having a beads-on-a-string appearance? A) diplococci B) palisade C) staphylococci D) streptobacilli E) streptococci

7) The ability of certain bacterial cells to take on different cell shapes is known as A) fission. B) pallidic. C) pleomorphic. D) pyloric. E) meiosis.

8) Which of the following is incorrect when E. coli cause a UTI? A) When infection has been established, the E. coli return to being motile rods that swim away from biofilms to perpetuate infections. B) Within the first few hours of invading host tissues, E. coli cells triple in size. C) When inside host cells, E. coli exist as nonmotile rods. D) As the infection progresses, E. coli pass through a stage where they appear as cocci. E) It is believed that E. coli avoid the host immune response by assuming a filamentous form.

9) Most prokaryotic cells reproduce A) by meiosis. B) extremely quickly. C) sexually. D) by binary fission. E) by mitosis.

10) Membrane proteins perform all of the following functions except A) anchors. B) receptors. C) enzymes. D) transporters. E) blocks.

10)

11) How can cells increase the fluidity of their plasma membrane? A) move to colder temperatures B) a lower proportion of unsaturated fats in the fatty acid portion of phospholipids C) integrating steroid-based lipids like cholesterol in membranes D) shorter phospholipids in the plasma membrane E) remove double bonds in the hydrocarbon backbone

11)

12) In order to maintain a fluid plasma membrane in cold conditions, bacteria commonly have A) phospholipids more concentrated. B) more short unsaturated fatty acids in their phospholipids. C) phospholipids less concentrated. D) more longer saturated fatty acids in their phospholipids. E) more cholesterol in their phospholipids.

12)

13) How does the plasma membrane of bacteria and archaea differ? A) Archaea have phospholipids built from branched fatty acids. B) Bacteria build only lipid monolayers. C) Bacteria have phospholipids built from branched fatty acids. D) Archaea build only lipid monolayers. E) Archaea have phospholipids built from linear fatty acids.

13)

14) How does the cell wall of bacteria and archaea differ? A) Bacteria have a lot of diversity in the makeup of their cell walls. B) Bacteria use peptidoglycan. C) Archaea use peptidoglycan. D) Bacteria use pseudopeptidoglycan. E) Archaea have little diversity in the makeup of their cell walls.

14)

15) Why are Gram-negative bacteria more resistant than Gram-positive bacteria to damage by certain chemical agents like lysozyme? A) Gram-negative bacteria have porins. B) Gram-negative bacteria contain peptidoglycan in their cell wall. C) Gram-negative bacteria lack a cell wall. D) Gram-negative bacteria have an outer membrane as part of their cell wall. E) Gram-negative bacteria have a thicker layer of peptidoglycan in their cell wall.

15)

16) In which of the following environments do Gram-negative bacteria have an advantage? A) abrasive environment B) dry environment C) wet environment D) needing to adhere to a host E) mechanical crushing

16)

17) Why is the acid-fast stain clinically useful? A) It confirms the results of the Gram stain. B) It confirms that a single dose of antibiotics is enough to kill the bacteria. C) It identifies the causative agents of leprosy and tuberculosis. D) It identifies the causative agent of certain fungal infections. E) It identifies the causative agent of strep throat and Scarlet fever.

17)

18) Why is it so difficult to kill acid-fast bacteria? A) They are just as difficult to kill as Gram-positive bacteria. B) The bacteria are able to quickly break down several types of antibiotics before the concentration can reach dangerous levels. C) Mycolic acid makes it very difficult for nutrients and gases to enter or exit cells. D) The acid in the bacteria denatures most antibiotics before they can work. E) The bacteria are very motile and can travel to areas with a lower concentration of hazardous chemicals.

18)

19) How are L-forms different than Mycoplasma bacteria? A) L-forms are susceptible to antibiotics that target the cell wall. B) L-forms live inside animal cells. C) L-forms are resistant to certain environmental stresses like boiling and autoclaving. D) L-forms have never had a cell wall. E) L-forms live inside plant cells.

19)

20) Which type of cellular transport uses transport proteins and moves substances from an area of high concentration to an area of low concentration? A) facilitated diffusion B) simple diffusion C) phosphotransferase system D) secondary active transport E) primary active transport

20)

21) What term most correctly describes when energy released by the flow of an ion from high to low concentration fuels the transport of an unrelated substance from low to high concentration but in the same direction? A) phosphotransferase system B) tertiary active transport C) symport D) primary active transport E) antiport

21)

22) What happens when you place a bacterial cell into a hypertonic solution? A) lysis B) no effect on the cell C) plasmolysis D) The cell will burst. E) The cell will swell.

22)

23) Short, bristle-like structures that extrude from the cell surface are called A) pili. B) cilia. C) mating bridges. D) flagella. E) fimbriae.

23)

24) Which of the following structures allow bacteria to transfer genetic information through conjugation? A) pili B) slime layer C) capsule D) glycocalyx E) fimbriae

24)

25) Which of the following structures do not help the bacteria adhere to surfaces? A) flagella B) slime layer C) fimbriae D) capsule E) pili

25)

26) Bacteria that have flagella distributed all over the cell surface are described as (having) A) lophotrichous. B) monotrichous. C) periplasmic flagella. D) peritrichous. E) amphitrichous.

26)

27) Periplasmic flagella are unlike most flagella because they A) move their flagella in a clockwise direction. B) are located in the space between the peptidoglycan and the outer membrane. C) are located in the space between the plasma membrane and the peptidoglycan. D) have fibers that stick into the cytoplasm for a better hold. E) move their flagella in a counter-clockwise direction.

27)

28) The genetic material of bacteria can be found in the A) nucleus. B) nucleolus. C) nucleosome. D) nucleoid. E) cytoskeleton.

28)

29) Which of the following is false about the bacterial cytoskeleton? A) The bacterial cytoskeleton contains actin and tubulin proteins. B) The bacterial cytoskeleton acts as scaffolding to organize cell division. C) The bacterial cytoskeleton is composed of long protein filaments. D) The bacterial cytoskeleton provides an overall general organization to the cytoplasm for a variety of biochemical processes. E) The bacterial cytoskeleton directs the construction of the rigid cell wall.

29)

30) 70S is the sedimentation rate of which of the following? A) eukaryotic cells B) eukaryotic cells, chloroplasts and mitochondria C) chloroplasts and mitochondria D) prokaryotic cells, chloroplasts and mitochondria E) prokaryotic cells

30)

31) Which of the following is true about ribosomes? A) Ribosomes build amino acids by linking together nucleic acids. B) Ribosomes are organelles made of RNA and carbohydrates. C) Antibiotics often take advantage of functional differences between prokaryotic and eukaryotic ribosomes. D) Prokaryotic ribosomes are also easily differentiated from eukaryotic ribosomes based on chemical composition. E) Prokaryotic ribosomes have a lower overall mass and diameter than eukaryotic ribosomes.

31)

32) Which of the following is not an example of an inclusion body? A) glycogen B) carboxysomes C) endosomes D) magnetosomes E) poly-β-hydroxybutyrate

32)

33) What is the function of a carboxysome? A) store energy B) protect against oxygen radicals C) fix carbon D) store carbon E) acts as a magnetic compass to guide bacteria

33)

34) Which of the following is true about endospores? A) Endospores are metabolically active structures. B) Endospores are only viable for a short time. C) Endospores are considered reproductive structures. D) Endospores are highly resistant to environmental stress such as heat, drying, freezing, and radiation. E) Endospores are susceptible to various chemicals.

34)

35) Which of the following does not enable bacterial endospores to be heat resistant? A) exosporium B) low water content C) high amount of dipicolinic acid D) spore coat E) peptidoglycan

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) Spirochetes move in a corkscrew-rotary motion due to a specialized periplasmic flagellum.

36)

37) Binary fission is more complicated than mitosis.

37)

38) Gram-positive bacteria stain purple when the Gram stain is complete.

38)

39) Prokaryotic cells that move in response to oxygen levels are said to display chemotaxis.

39)

40) Bacteria that have flagella at both poles of the cell are described as amphitrichous.

40)

41) A capsule is one type of glycocalyx that is fairly unorganized and loosely associated with the cell wall.

41)

42) Bacteria that have periplasmic flagella always have a spirochete shape.

42)

43) A bacteria's DNA can be found in the nucleus of the cell.

43)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 44) Explain the steps of binary fission. 45) If you were to design a pathogenic bacteria, justify why your bacteria would be Gram-positive or Gram-negative. 46) What about Pseudomonas aeruginosa makes it especially problematic in burn victims and cystic fibrosis patients?

47) Without using chemical agents, name two examples of how the bacterial cell wall can be damaged that would result in Gram-positive bacteria showing a Gram-negative result.

Answer Key Testname: UNTITLED17

1) B 2) C 3) C 4) A 5) D 6) E 7) C 8) B 9) D 10) E 11) C 12) B 13) A 14) B 15) D 16) C 17) C 18) C 19) C 20) A 21) C 22) C 23) E 24) A 25) A 26) D 27) B 28) D 29) A 30) D 31) E 32) C 33) C 34) D 35) E 36) TRUE 37) FALSE 38) TRUE 39) FALSE 40) TRUE 41) FALSE 42) TRUE 43) FALSE 44) Binary fission occurs in five main steps. First, the cell that is preparing to divide copies its DNA -containing chromosome, so that each daughter cell will receive a complete chromosome. Because the chromosome is tethered to the cell membrane, as the cell grows, the copied chromosomes separate and are drawn to opposite ends of the cell. Eventually the cell reaches a critical size and a septum (partition) begins to form near the midpoint. The septum, which is essentially the newly forming cell wall, eventually walls off the resulting two daughter cells from one another. The daughter cells may completely separate or they can remain associated to form a variety of cellular arrangements. 8

Answer Key Testname: UNTITLED17

45) My bacteria would be Gram-negative because the outer membrane could guard against damage by certain agents, including lysozyme, a variety of drugs, and some detergents and disinfectants. Because Gram-negative cells have a thin layer of peptidoglycan and the added protection of the outer membrane, they tend to be less sensitive to compounds like penicillin than Gram-positive bacteria are. Or the student could answer: My bacteria would be Gram-positive because those bacteria have cell walls that retain moisture longer due to their thic peptidoglycan layer, making these cells better at surviving in dry environments. The thick peptidoglycan layer protects Gram-positive cells from mechanical stresses like abrasion and crushing. Gram-positive bacteria also have teichoic acids, which stabilize the cell wall, help maintain shape, transport cations into the cell, and aid regulation of cell division. Teichoic acids also aid certain Gram-positive bacteria in causing disease by promoting adhesion to host tissues and protecting them from various antimicrobial compounds. 46) Pseudomonas aeruginosa is notorious for its efflux pumps, which have rendered the species resistant to whole families of antibiotics. It also uses pili to move along surfaces. 47) Gram-positive bacteria can show a Gram-negative result when the culture is too old or when bacteria produce endospores. Both of these result in damage to the cell wall as the bacteria get old and die or release the endospore.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Evidence in support of the endosymbiotic theory includes A) a single membrane enclosing the mitochondria and chloroplasts. B) linear DNA in mitochondria and chloroplasts. C) the presence of 70S ribosomes in mitochondria and chloroplasts. D) the presence of 70S ribosomes in mitochondria and chloroplasts and a single membrane enclosing the mitochondria and chloroplasts linear DNA in mitochondria and chloroplasts. E) the presence of 70S ribosomes in mitochondria and chloroplasts and a single membrane enclosing the mitochondria and chloroplasts.

2) Which of the following statements describes eukaryotic cells? A) They may contain 80S or 70S ribosomes in their cytoplasm. B) They have a cell wall. C) They may divide using binary fission, mitosis, or meiosis. D) They contain membrane-bound organelles such as a nucleus. E) They may contain a cell wall made of peptidoglycan.

3) You have discovered a compound that inhibits the placement of sterols in the plasma membrane. What can you deduce about the efficacy of this drug? A) This drug may be broadly effective against prokaryotic cells. B) This drug may be broadly effective against eukaryotic cells but may be toxic in human patients. C) This drug may be broadly effective against both prokaryotic and eukaryotic cells. D) This drug may be broadly effective against both prokaryotic and eukaryotic cells but may be toxic in human patients. E) This drug may be broadly effective against eukaryotic cells.

4) A similarity between mitosis and meiosis is A) production of genetically unique daughter cells. B) production of daughter cells with the same number of chromosomes as the parent. C) copying DNA before the cell divides. D) sexual reproduction. E) two sequential cell divisions.

5) Which of the following processes is incorrectly matched to its description? A) Pinocytosis: Imports dissolved substance using small vesicles B) Phagocytosis: Imports undissolved substances but not whole cells or viruses C) Receptor-mediated endocytosis: Uses specific binding between structures on the plasma membrane binding to ligands D) Exocytosis: Exports materials into a cell E) Endocytosis: Imports materials into a cell

6) Which process is pictured?

A) receptor-mediated endocytosis B) pinocytosis C) endocytosis D) phagocytosis E) exocytosis 7) Which group is not a kingdom-level classification of eukaryotic organisms? A) protozoa B) plants C) fungi D) protista

7) E) animals

8) You have isolated a new organism which has eukaryotic cells, is multicellular, grows as hyphae, does not perform photosynthesis, and has a cell wall. This organism most likely belongs to which kingdom? A) Fungi B) Bacteria C) Archaea D) Protista E) either Fungi or Protista

9) You have isolated a new eukaryotic organism which is unicellular and performs photosynthesis. The organism is most likely classified as a(n) A) fungus. B) animal. C) plant-like protista. D) fungi-like protista. E) bacterium.

10) Most helminthic parasites spend at least some part of their life cycle in the A) skin. B) gastrointestinal tract. C) respiratory tract. D) cardiovascular system. E) genitourinary tract.

10)

11) Which statement does not describe helminthic parasites? A) All are hermaphroditic. B) All belong to one of two groups: roundworms or flatworms. C) All reproduce sexually. D) All tend to have complex life cycles that can involve different host species. E) An important mode of transmission is ingestion of the eggs or organism from feces-contaminated food and water.

11)

12) Hyphae are A) the main growth form of pathogenic fungi when they are infecting humans. B) collections of fungal growth on the skin. C) a unicellular yeast-like form found in some fungi. D) a collection of tubular structures that result from fungal growth. E) reproductive structures in fungi.

12)

13) Which of the following are asexual fungal spores?

13)

A) conidiospores and sporangiospores B) any type of fungal spore can be asexual or sexual depending on how it formed C) ascospores, basidiospores, and conidiospores D) ascospores, basidiospores, and zygospores E) No types of fungal spores are asexual.

14) Fungal infections are called A) basidium. B) sporgangia. C) dimorphic. D) mycoses. E) coencytic.

14)

15) Which persons may be at increased risk for mycoses? A) those with weakened immune systems B) those who have not received the recommended vaccine schedule C) those who have had their normal microbiome disrupted by antibiotic therapy D) either those with weakened immune systems or those who have had their normal microbiome disrupted by antibiotic therapy E) either those with weakened immune systems or those who have not received the recommended vaccine schedule

15)

16) Which feature is not found in protozoans? A) usually heterotrophic B) unicellular C) may reproduce sexually or asexually D) no cell walls E) performs photosynthesis

16)

17) Amoeboid protozoans A) are always free-living. B) move via cilia. C) may exist in the environment encased in a tough protective layer called a cyst. D) move via cilia and are always free-living. E) move via cilia, are always free-living and may exist in the environment encased in a tough protective layer called a cyst.

17)

18) A patient presents with symptoms of severe gastrointestinal distress. Bacterial and viral pathogens are ruled out. A protozoan which moves via hair-like appendages is observed upon microscopic examination of the patient's stool. The most likely cause of the infection is A) ergot toxin, a fungal mycotoxin. B) Balantidium coli, a ciliated protozoan. C) Entamoeba histolytica, an amoeboid protozoan. D) Giardia lamblia, a flagellated protozoan. E) Plasmodium, an apicomplexan.

18)

19) A researcher discovers a chemical compound which prevents the incorporation of ergosterol in the plasma membrane We can predict that this compound would be toxic to which kinds of organisms? A) fungi B) plants C) bacteria D) viruses E) animals

19)

20) Which pairing of organism and the chemical component of its cell wall is matched incorrectly? A) Bacteria: peptidoglycan B) Plants: cellulose C) Fungi: chitin D) Protista: cellulose, silica, or other components E) Animals: cholesterol

20)

21) The role of the glycocalyx in eukaryotic cells may include A) protection against mechanical and osmotic stress, tissue development, and transport processes. B) protection against mechanical and osmotic stress. C) tissue development. D) tissue development and transport processes. E) transport processes.

21)

22) Which does not describe eukaryotic flagella? A) whip-like motion B) 9+2 arrangement of microtubules C) anchored by a basal body connected to a centriole D) flagellin protein E) plasma membrane-enclosed

22)

23) Which picture shows the flagella? A)

23)

24) A chemical compound which specifically disrupts the 9+2 microtubule arrangement would be a potential drug candidate as a(n) A) antimicrobial targeting amoeboid protozoans. B) herbicide (weed-killer). C) drug targeting fungal pathogens. D) antibiotic targeting motile bacteria. E) contraceptive drug disabling motility of human sperm.

24)

25) Where are cilia found in the human body? A) female reproductive system B) oral cavity C) upper respiratory tract D) large intestine E) lining blood vessels

25)

26) Prokaryotic and eukaryotic ribosomes share which of the following features? A) composed of protein and rRNA B) composed of a large and a small subunit and composed of protein and rRNA C) function is making DNA D) contain a large and a small subunit E) composed of protein and rRNA, composed of a large and a small subunit, and function is making DNA

26)

27) Which statement is not true about eukaryotic ribosomes? A) Ribosomes found in mitochondria are 70S rather than the 80S type found in the cytoplasm. B) Bound ribosomes are always bound while free ribosomes are always free. C) Bound ribosomes are attached to the endoplasmic reticulum (ER). D) Both bound and free ribosomes consist of a 40S and a 60S subunit. E) Bound ribosomes produce proteins that are destined for secretion from the cell.

27)

28) Which is not a function which the cytoskeleton performs? A) transport of vesicles and organelles B) movement of the cell C) movement of chromosomes during cell division D) protection from external forces E) passive transport of substances through the plasma membrane

28)

29) Which fiber of the cytoskeleton is matched correctly with its function or structure? A) Microfilaments: Interact with the motor protein myosin B) Microtubule: Composed of the protein actin C) Microfilaments: Polymerize to form the spindle during mitosis D) Microtubule: Contribute tensile strength to the cytoskeleton E) Intermediate filament: Polymerize and depolymerize to facilitate cell movement

29)

30) A chemical compound is discovered which prevents the actin protein from interacting with the myosin protein. What can you deduce about this compound? A) It might be an effective compound against amoeboid protozoans but might also be too toxic to human cells to be used. B) It might be an effective compound against amoeboid protozoans. C) It might be an effective compound against bacterial pathogens. D) It might be an effective compound against bacterial pathogens amoeboid protozoans. E) It might have toxic effects against all eukaryotic cells.

30)

31) The primary function of the nucleus is A) serving as the site of ribosome synthesis of protein. B) serving as the site of most of the cell's chemical reactions. C) housing the cell's DNA. D) production of the cell's energy molecule, ATP. E) digestion and processing of nutrients.

31)

32) The chromatin is A) a liquid filling the nucleus. B) an organelle which is continuous with the nuclear envelope. C) a collection of DNA and protein. D) the site where ribosomal subunits begin their development. E) the entry and exit point for material into and out of the nucleus.

32)

33) Which structure pictured is the site of synthesis of proteins destined for secretion?

33)

A) smooth endoplasmic reticulum B) rough endoplasmic reticulum C) rough and smooth endoplasmic reticulum D) rough and smooth endoplasmic reticulum, and cisternae E) cisternae 34) The rough ER and the smooth ER are distinguished from each other by A) the presence or absence of both DNA and membrane-bound ribosomes. B) synthesis of lipids by the rough ER and synthesis of proteins by the smooth ER. C) the presence or absence of membrane-bound ribosomes. D) the presence or absence of membrane-bound ribosomes and the synthesis of lipids by the rough ER and the synthesis of proteins by the smooth ER. E) the presence of absence of DNA.

34)

35) Vesicles that bud off the ER are typically shuttled to the modified, sorted, and distributed. A) plasma membrane B) nucleus C) lysosome D) Golgi apparatus E) mitochondria

where their contents can be

35)

36) Which type of vesicle/vacuole is incorrectly matched with its description? A) Secretory vesicle: Replenishes the lipid bilayer and deliver proteins for incorporation into the membrane B) Peroxisome: Protects the cell from hydrogen peroxide and other toxic oxygen intermediates C) Vacuole: Contains water and substances such as nutrients, toxins, or waste products D) Transport vesicle: Moves substances to diverse cellular destinations within the cell E) Lysosome: Contains hydrolytic enzymes that break down substances engulfed by the cell

36)

37) Mitochondria share all the following features with bacteria except A) 80S ribosomes. B) 70S ribosomes. C) linear DNA and 80S ribosomes. D) linear DNA. E) 70S and 80S ribosomes.

37)

38) Mitochondria do not participate in which function? A) programmed cell death B) production of amino acids and vitamins C) regulation of cell division D) production of ATP E) motility

38)

39) Which portion of the mitochondria is folded to create a large surface area?

39)

A) outer membrane B) intercristal space C) matrix D) inner and outer membranes E) inner membrane TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 40) According the endosymbiont theory we can reason that the merging event that led to the mitochondria occurred before the merging event that led to the chloroplast because all eukaryotic cells which have chloroplasts also have mitochondria, but all cells that have mitochondria do not necessarily have chloroplasts.

40)

41) Binary fission, mitosis, and meiosis all produce genetically identical daughter cells.

41)

42) The kingdom Protista contains species which have plant-like features, others which contain animal-like features, and still others that contain fungal-like features. This is because scientists do not have a set of standard features by which to group them.

42)

43) The four groups of protozoans are grouped by their mode of reproduction.

43)

44) Bacterial plasma membranes differ from eukaryotic plasma membranes in that bacterial membranes always contain cholesterol while eukaryotic membranes rarely do.

44)

45) Animal cells are unique among all other eukaryotic groups in that they universally lack a cell wall.

45)

46) Unlike antibiotics which target the 70S bacterial ribosomes, there are no known chemical substances which can bind to 80S eukaryotic ribosomes.

46)

47) Cells which are active and have high energy demand will have more mitochondria than cell that are less active and have lower energy demand.

47)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 48) Describe the sequence of events in the evolution of eukaryotic cells as described by the endosymbiotic hypothesis. List four pieces of evidence which support this theory. 49) Protozoan infections are common in (though definitely not limited to) developing countries where limited medical and laboratory facilities may hinder diagnosis. Each of the four groups of protozoans may be identified by certain characteristics visible under the microscope. Name the groups and explain those characteristics which lead to identification. 50) Antimicrobial therapies against fungal or protozoan pathogens are challenging to develop because these microbes have eukaryotic cells just as humans do. However, differences do exist between animal cells and the cells of these microbes which provide the opportunity to develop therapies which target these unique structures or molecules. Describe three cellular components of fungal and/or protozoan cells which are not found in animal cells which could be potential targets for drug therapy. 51) Eukaryotic organelles may be targeted by environmental toxins or microbial pathogens. Describe two examples of disease in humans which result from damage or malfunction to an organelle or other intracellular structure.

Answer Key Testname: UNTITLED18

1) C 2) D 3) B 4) C 5) B 6) E 7) A 8) A 9) C 10) B 11) A 12) D 13) A 14) D 15) D 16) E 17) C 18) B 19) A 20) E 21) C 22) D 23) A 24) E 25) C 26) B 27) B 28) E 29) A 30) A 31) C 32) C 33) B 34) C 35) D 36) A 37) C 38) E 39) E 40) TRUE 41) FALSE 42) TRUE 43) FALSE 44) FALSE 45) TRUE 46) FALSE 47) TRUE

Answer Key Testname: UNTITLED18

48) The endosymbiotic theory describes the evolution of eukaryotic cells as a series of sequential, cell -merging events between a eukaryotic ancestor and certain prokaryotes. First, a non-photosynthetic prokaryote merged with the ancestral cell. Over time, the prokaryote lost the ability to live independently and evolved into the mitochondria. Later, descendants of these cells merged again with a photosynthetic prokaryote which became the chloroplast. Evidence for the endosymbiotic theory include the following: mitochondria and chloroplasts each contain circular DNA and 70S ribosomes similar to those found in bacteria, they are bound by a double-membrane within the eukaryotic cell, they are similar in size to bacteria, and replicate by a process similar to binary fission. A number of mitochondrial genes resemble genes found in certain bacteria (namely rickettsial species) while genes in the chloroplast resembles genes found in cyanobacteria. 49) Protozoans are grouped into four categories by their means of motility of their mature stage which can be observed in a microscope. 1) Amoeboid protozoans move by means of cytoplasmic extensions called pseudopods. 2) Flagellated protozoans move by one or more "whip-like" flagella. 3) Ciliated protozoans move by hair-like appendages called cilia which cover the entire surface of the cell. 4) Spore-forming protozoans do not have flagella, cilia, nor pseudopods in their mature form; they move by gliding. 50) All eukaryotic cells contain sterols in their plasma membranes; however, the specific type of sterol differs. Animal cells contain cholesterol while fungal and protozoan cells contain a variety of different sterols with ergosterol being a common example. Animal cells universally lack a cell wall while fungi have cell walls made of chitin while protists cell walls may contain cellulose, calcium carbonate, xylan, silica, and a variety of other protein- and carbohydrate-based substances. Flagella or cilia are found in flagellated protozoans or ciliate protozoans respectively. Animal cells do not generally contain these structures with two important exceptions. Many animal sperm are flagellated, and the epithelial cells of the upper airway in vertebrate animals contain cilia. The glycocalyx in different organisms may be made of different types of carbohydrates, glycoproteins, and glycolipids. The glycocalyx of pathogenic fungi and protozoans is known to impact infectivity and immune responses. 51) The bacteria Shigella and E. coli produce a toxin which binds to the 60S ribosomal subunit of eukaryotes. The plant toxin ricin also targets this ribosomal subunit. The bacteria Salmonella enterica and Listeria monocytogenes both alter fibers in the host cell cytoskeleton as a means of entering cells. Certain anticancer drugs target the cytoskeleton in tumor cells. Several pathogens including the protozoan Toxoplasma gondii induce a stress response in the endoplasmic reticulum which can lead to tissue damage or cancer. Damage to mitochondria due to exposure to toxic oxygen products is associated with aging and other chronic diseases such as Parkinson's, cancer, atherosclerotic heart disease, and type II diabetes.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following terms refers to the genetic makeup of an organism? A) purine B) heritable C) genotype D) phenotype E) primosome

2) Where can the DNA of prokaryotic cells be found? A) in numerous linear chromosomes B) nucleoid C) around histones D) nucleus E) nucleolus

3) Which of the following nitrogen bases is found only in RNA and NOT in DNA? A) cytosine B) thymine C) uracil D) adenine

3) E) guanine

4) Which direction are phosphodiester bonds of DNA usually built in? A) 5' → 1' B) 1' → 5' C) 5' → 3' D) 3' → 5' E) Any direction is fine and will not affect the function of the DNA strand.

5) RNA differs from DNA in all of the following ways except A) RNA has a hydroxyl group on the 2' carbon. B) RNA is single stranded. C) RNA has directionality. D) there are several different types of RNA including mRNA, tRNA, and rRNA. E) in RNA, uracil (U) replaces thymine (T).

6) The primary flow of genetic information in cells is from

A) protein → DNA→ RNA. B) protein → RNA → DNA. C) RNA→ DNA → protein. D) DNA → protein → RNA. E) DNA → RNA → protein. 7) DNA replication is A) going to result in relatively few mutations. B) the exact same for prokaryotes and eukaryotes. C) error prone. D) the process a cell uses to make protein. E) slow.

8) Which of the following statements about the primosome is false? A) The primosome is recruited to the origin of replication. B) The primosome includes RNA polymerase to build the protein. C) The primosome is responsible for starting DNA replication. D) The primosome includes helicase to unwind the DNA. E) The primosome includes primase to lay down RNA primers that will jump-start replication.

9) Helicase A) creates the replication fork. B) relieves coiling tension that develops as the helix is unwound. C) causes a bubble of single-stranded DNA to form. D) unwinds the DNA. E) allows for DNA polymerase III to bind to the DNA.

10) As replication proceeds in a prokaryotic cell, how many replication forks exist on one chromosome? A) 1 B) 2 C) 3 D) 4 E) 5

10)

11) Which of the following statements about the lagging strand is false? A) It builds in the opposite direction of the helix unwinding. B) It is a discontinuous process. C) It is where one would find Okazaki fragments. D) It uses only one molecule of DNA polymerase I. E) It synthesizes many RNA primers.

11)

12) Eukaryotic replication differs from prokaryotic replication, because eukaryotic replication A) has more DNA to copy. B) involves only one circular chromosome. C) involves more protein factors. D) has multiple replication initiation sites. E) takes longer to copy.

12)

13) Which of the following statements about protein synthesis is false? A) Protein synthesis has two main stages: replication and transcription. B) Protein synthesis is where genetic information is read and used to create gene products. C) Protein synthesis is responsible for most physical and functional cell features. D) Protein synthesis can be disrupted by many antibiotics. E) Protein synthesis is central to life.

13)

14) Which of the following statements about transcription in prokaryotes in false? A) It uses RNA polymerase as the main enzyme. B) It uses DNA as the template to make RNA. C) It uses a lot of cellular energy. D) It is tightly regulated by the cell. E) It occurs in the nucleus.

14)

15)

RNA carries a genetic message in triplet code (codons) and is translated to build a protein. A) Transfer B) Messenger C) Junk D) Alternative E) Ribosomal

15)

16) The genetic code A) encodes for 18 amino acids. B) has 60 codons. C) relies on codons made up of DNA. D) contains sense codons and nonsense codons. E) uses a quartet code to encode the codons.

16)

17) Which of the following statements about reverse transcription is false? A) Reverse transcription is performed by certain viruses and human cells. B) Reverse transcription builds copy DNA (cDNA). C) Reverse transcription requires a particular initiation sequence. D) Reverse transcription uses special enzymes called reverse transcriptase. E) Reverse transcription uses RNA as a template.

17)

18) Introns A) are sometimes left in the mRNA sequence for alternative splicing. B) are removed by a complex called the spliceosome. C) are only found in eukaryotes. D) are considered to simply be junk DNA. E) are removed from mRNA in the cytoplasm.

18)

19) Which of the following statements is false? A) There are 22 amino acids that are genetically encoded by codons. B) In some species, one stop codon has been swapped out for one of the nonstandard amino acids. C) Four amino acids are considered nonstandard. D) There are hundreds of amino acids found in nature. E) Nonstandard amino acids are found in prokaryotes and eukaryotes.

19)

20) Which of the following statements about post-translational modifications is false? A) Post-translational modifications are often required for a protein to function. B) Additional inorganic factors could be added. C) Post-translational modifications provide a way for cells to regulate gene product functionality. D) Post-translational modifications can include the addition of extra amino acids. E) Additional organic factors could be added.

20)

21) Which of the following statements about constitutive genes is false? A) Constitutive genes account for less than 20 percent of a cell's genes. B) Constitutive genes are expressed at any given time. C) Constitutive genes function differently than facultative genes. D) Constitutive genes produce their proteins when a cell encounters a specific environmental change. E) Constitutive genes are referred to as housekeeping genes.

21)

22) Which of the following statements about pre-transcriptional regulation is false? A) It helps cells control how often transcription occurs. B) It is managed by transcription factors. C) It helps cells control when transcription occurs. D) It allows organisms to rapidly respond to frequent and dramatic changes in the environment. E) It is the one way cells can manage to control protein synthesis.

22)

23) Which of the following statements about an inducible operon is false? A) When off, the repressor binds to the operator. B) It is off by default. C) Certain conditions activate transcription. D) When off, RNA polymerase is blocked by the operator. E) When present, an inducer will inactivate the repressor.

23)

24) Which of the following statements is true about epigenetic regulation? A) DNA methylation is one example of epigenetic regulation that is only found in prokaryotes. B) Epigenetic regulation is completely understood. C) Epigenetic regulation is unable to affect a cell's phenotype. D) Epigenetic regulation is a way to control protein synthesis. E) Epigenetic regulation changes the sequence of DNA nucleotides.

24)

25) Which of the following statements is false about quorum sensing? A) Quorum sensing allows bacteria to alter their protein synthesis in response to changes in population density. B) Quorum sensing allows unicellular organisms to coordinate their processes. C) Bacteria can communicate using chemical messengers called autoinducers. D) Coordinated protein synthesis through quorum sensing is the foundation for forming biofilms. E) Bacteria that experience quorum sensing have a decreased chance of survival.

25)

26) All of the following are examples of post-transcriptional regulation except A) in prokaryotic cells, small noncoding RNAs that work in post-transcriptional regulation include small RNAs. B) cells can regulate translation by affecting how readily ribosomes associate with mRNA to read it. C) cells can regulate how mRNA is spliced and exported out of the nucleus before translation occurs. D) in eukaryotic cells, small noncoding RNAs that work in post-transcriptional regulation include microRNAs and short interfering RNAs. E) cells can regulate translation by methylating certain DNA nucleotides.

26)

27) Which of the following statements about mutations is false? A) Multicellular organisms evolve faster than unicellular organisms. B) Mutations are essential to variation within species. C) A mutation is a change in the genetic material of a cell or virus. D) A mutation in a single-celled organism is more likely to be passed to daughter cells than a multicellular organism. E) Mutations are essential to evolution within species.

27)

28) Which of the following terms is correctly matched with its description? A) Substitution mutations: Occur when an incorrect amino acid is added. B) Substitution mutations: Occur when an incorrect fatty acid is added. C) Point mutations: Occur when an incorrect carbohydrate is added. D) Deletion mutations: Occur when one or more amino acids are removed from a protein sequence. E) Insertion mutations: Occur when a cell adds one or more nucleotides to its genome sequence.

28)

29) A

29)

mutation does not change the amino acid sequence of a protein. A) missense B) deletion C) nonsense D) frameshift

E) silent

30) Frameshift mutations can do all of the following except A) substitute one amino acid for another. B) insert or eliminate an amino acid. C) change the protein's amino acid sequence. D) render the protein useless to the cell. E) insert or delete a DNA base. 31) Naturally occurring mutations are often referred to as A) deleterious B) spontaneous C) unnoticed D) insertion E) neutral

30)

mutations.

31)

mutagens are agents that can introduce genetic change through recombination. A) Organic B) Chemical C) Frameshift D) Biological E) Physical

32)

33) In the Ames test, what happens when his- bacteria are exposed to a chemical and experience a higher level of growth than the control? A) The his- bacteria utilized DNA repair tools to fix the mutation.

33)

32)

B) A reversion mutation allowed the his- bacteria to regain their ability to make histidine (revert to his+). C) The reversion rate is lower than seen for spontaneous mutations. D) The his- bacteria now utilized histidine from the media. E) The tested chemical is regarded as a non-mutagen.

34) Which of the following statements about thymine dimers is false? A) Patients with xeroderma pigmentosum have faulty DNA repair mechanisms. B) If resulting mutations accumulate, it can result in cancers. C) They are repaired by excision repair. D) They can be produced by exposure to UV light. E) They are repaired by one enzyme that can clip out, lay down new nucleotides, and seal the gap.

34)

35) Which of the following statements about plasmids is false? A) Plasmids are commonly shared among cells by horizontal gene transfer mechanisms. B) Molecular biologists often use plasmids to generate cell lines that make useful products for medical applications. C) Plasmids are nonchromosomal DNA segments found in bacteria and a number of eukaryotic cells. D) If present, plasmids are always essential to cell survival. E) Plasmids are easily manipulated in the laboratory.

35)

36) Key mechanisms of horizontal gene transfer include all of the following except A) transformation. B) conjugation. C) transduction. D) transposons. E) reproduction.

36)

37) Which of the following statements about conjugation is false? A) Conjugation can be a problem because fertility plasmids often carry genes that endow cells with drug resistance or the ability to produce toxins. B) In conjugation a bacterium forms a small hollow tube called a pilus. C) In conjugation a bacterium carries a fertility plasmid. D) Conjugation is sexual reproduction for bacteria. E) In conjugation a bacterium attaches to a neighboring bacterial cell that lacks a fertility plasmid.

37)

38)

is when the fertility plasmid merges with the bacterial cell's chromosome and ceases to be an independent plasmid in the cytoplasm. A) Transfection B) Transformation C) Transduction D) Conjugation E) Recombination

39) How does transformation differ from conjugation? A) Transformation requires only fresh DNA be used. B) Transformation can only exchange DNA between bacteria of the same species. C) Transformation requires DNA to be on a plasmid. D) Transformation involves a pilus. E) Transformation takes up DNA from the environment.

39)

40) Which of the following statements is true about specialized transduction? A) Bacteriophage undergoing specialized transduction integrate their DNA into a random region of the host cell's genome. B) Specialized transduction always directs the production of new phage particles immediately upon infecting the host bacterium. C) A bacteriophage may at some point become reactivated, excise itself and surrounding bacterial genes from the genome, and begin to build new phage particles. D) Specialized transduction occurs in all bacteriophage except the temperate phages. E) Specialized transduction requires that bacteriophage infect at least two different cells to be carried out.

40)

41) Which of the following is true about retrotransposons? A) Retrotransposons never remain in their original location. B) Retrotransposons can use a "copy-and-paste" strategy. C) Retrotransposons can use a "cut-and-paste" strategy. D) Retrotransposons rely on an RNA intermediate to insert into a new part of the genome. E) Retrotransposons do not require an RNA intermediate.

41)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 42) An organism's genotype influences its phenotype.

42)

43) Gyrase breaks the hydrogen bonds between DNA strands and unwinds the DNA strands while topoisomerases relieve the coiling tension that develops as the helix unwinds.

43)

44) DNA replication is a semiconservative process.

44)

45) A sequence of cDNA would contain introns but no exons.

45)

46) Introns shouldn't be perceived as junk or a nuisance, rather, they provide an opportunity for genetic diversity.

46)

47) A repressible operon produces a repressor that is inactive from the start.

47)

48) A reversion mutation is when a base-substitution mutation is changed back to the original DNA sequence.

48)

49) Many mutagens cause a rate of mutation that promotes the development of cancers; such mutagens are called carcinogens.

49)

50) DNA transposons rely on the enzyme reverse transcriptase to insert a copy of cDNA into a new location in the genome.

50)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 51) Using the central dogma of molecular biology, explain how an organism's genotype influences its phenotype. 52) What are the differences between DNA replication on the leading and lagging strands and why do they exist? 53) Explain how a bacterium living in a biofilm behaves very similar to a primitive multicellular organism. 7

54) Both prokaryotes and eukaryotes have several types of pre and post-transcriptional regulation. What advantage does pre-transcriptional regulation have over post-transcriptional regulation and vice versa? Name three examples of each type of regulation. 55) Describe the four scenarios of Griffith's experiment in the 1920s and summarize the main conclusion.

Answer Key Testname: UNTITLED19

1) C 2) B 3) C 4) C 5) C 6) E 7) A 8) B 9) D 10) B 11) D 12) B 13) A 14) E 15) B 16) D 17) C 18) B 19) C 20) D 21) D 22) E 23) D 24) D 25) E 26) E 27) A 28) E 29) E 30) A 31) B 32) D 33) B 34) E 35) D 36) E 37) D 38) E 39) E 40) C 41) D 42) TRUE 43) FALSE 44) TRUE 45) FALSE 46) TRUE 47) TRUE 48) FALSE 49) TRUE 50) FALSE 9

Answer Key Testname: UNTITLED19

51) An organism's genetic makeup or, genotype, is used to produce their mRNA through transcription. The mRNA is used to produce their proteins through translation. It is these proteins that are responsible for shaping the phenotype of the organism. This flow of information is referred to as the central dogma of molecular biology and closely links one's genotype to its phenotype. 52) The leading strand only requires primase to lay down one RNA primer while many RNA primers are needed on the lagging strand. DNA polymerase III is basically the only polymerase that is used on the leading strand to build DNA off of the one RNA primer, but the lagging strand also requires DNA polymerase I to replace the many RNA primers used. Ligase is also needed extensively on the lagging strand to glue the Okazaki fragments together after DNA polymerase I has done its job. Since the leading strand is one continuous read, Okazaki fragments are not found on this strand. 53) Bacteria living in a community or biofilm produces chemicals called autoinducers. Bacteria are able to use these signals to better sense what is occurring in their community and this is referred to as quorum sensing. Quorum sensing allows bacteria to alter their protein synthesis in response to changes in the density of the population. In this way, quorum sensing allows unicellular organisms to coordinate their processes and behave more collectively, almost like a primitive multicellular organism. 54) Pre-transcriptional regulation is very useful to the cell because it can save the cell a lot of energy and additional resources (for example RNA nucleotides) by stopping transcription before it even starts. Although post-transcriptional regulation will have already used some of the cell's energy and resources, its major advantage is that the cell will be able to respond faster to environmental changes. Examples of pre-transcriptional regulation include: operons, quorum sensing, epigenetic control (such as DNA methylation), and recruitment of transcription factors. Examples of post-transcriptional regulation include: recruiting ribosomes to mRNA, controlling mRNA stability, small noncoding RNAs, riboswitches, and eukaryotes can control RNA processing and nuclear export. 55) In scenario 1, Griffith infected a mouse with a living encapsulated bacteria and the mouse died. In scenario 2, Griffith infected a mouse with a living nonencapsulated bacteria and the mouse lived. In scenario 3, Griffith infected a mouse with a heat-killed encapsulated bacteria and the mouse lived. In scenario 4, Griffith infected a mouse with a living nonencapsulated bacteria and a heat-killed encapsulated bacteria and the mouse died. Live encapsulated bacteria were found in the mouse's blood. To conclude, the nonencapsulated bacteria were able to take up DNA from the killed encapsulated bacteria via transformation. This changed the nonpathogenic bacteria into the virulent variety. Griffith's experiments demonstrated that environmental DNA could transform bacteria and help pathogens evolve.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Viruses are considered to be non-living pathogens for which reason? A) their ability to synthesize only some of their own components B) their lack of metabolic processes C) their unique type of cells D) their unique type of cells and their lack of metabolic processes E) their extremely small size

2) Compared to both prokaryotic and eukaryotic cells, viruses A) are not filterable. B) lack genetic material. C) are generally smaller. D) lack proteins. E) have similar metabolic processes.

3) A previously undescribed infection has been detected among inhabitants in an isolated village in a remote tropical rainforest. When serum from an infected individual is passed through a filter, the infection can be transmitted to laboratory animals. Nothing is observed when the serum is examined with a light microscope at the highest magnification. Biochemical tests show the presence of RNA and protein but no carbohydrates or lipids. This data is consistent with what type of infectious agent? A) prokaryote B) virus C) eukaryote D) either a virus or a prokaryote E) either a virus, a prokaryote, or a eukaryote

4) Which statement is not true about the virus capsid? A) The capsid functions as a package for the viral genetic material. B) Both bacteriophage and animal viruses have capsids. C) The capsid determines the shape of the virus. D) The capsid is made of one or more types of protein subunits. E) Because the capsid is not essential to the virus, it is not a useful target for antiviral drugs.

5) When a virus has an envelope, A) it is always an RNA-containing virus. B) it is always a bacteriophage. C) it likely escapes its host cell by budding. D) it may escape its host cell either by budding or by lysis. E) it likely escapes its host cell by lysis.

6) Viral spikes A) show specificity in binding to particular structures on the host cell. B) allow the virus to attach and enter host cells but do not show specificity for a particular structure on the host cell. C) may be a target for the host immune system. D) allow the virus to attach and enter host cells. E) allow the virus to attach and enter host cells, may be a target for the host immune system, and show specificity in binding to particular structures on the host cell.

7) Which picture shows an icosahedral enveloped virus with spikes? A)

8) Which genomic arrangement has not been found in viruses? A) a combination of DNA and RNA in the same virus B) double-stranded RNA C) single-stranded DNA D) single-stranded RNA E) double-stranded DNA

9) All viruses must use their genome to produce produce . A) proteins; DNA B) proteins; mRNA C) DNA; mRNA D) mRNA; proteins E) DNA; proteins

, which is then used by the host cell to

10) Retroviruses use the enzyme reverse transcriptase to A) transcribe mRNA from a DNA genome. B) direct the production of DNA from a single-stranded RNA genome. C) synthesize a hybrid molecule with one DNA stranded base-paired to the complementary RNA strand. D) synthesize sense-stranded mRNA from an antisense RNA genome. E) synthesize double-stranded RNA.

10)

11) A newly-discovered double-stranded RNA virus which infects animal cells is found to contain a unique enzyme which synthesizes double-stranded RNA using an RNA template. Which of the following statements is likely to be true? A) This enzyme is coded for by a gene in the host cell. B) The enzyme probably came from the host animal cell and is coded for by a gene in the host cell. C) This enzyme would not be a good antiviral drug target as the host cell likely has a similar enzyme which could be affected by such a drug. D) The virus must bring this enzyme into the host cell as synthesizing RNA from an RNA template does not happen in animal cells. E) The enzyme probably came from the host animal cell.

11)

12) Which of the following are contributors to viral genome evolution? A) superior proofreading by RNA polymerases compared to DNA polymerases B) quick replication time and the large number of virions released within a host C) the large number of virions released within a host D) quick replication time and superior proofreading by RNA polymerases compared to DNA polymerases E) quick replication time

12)

13) Which description of antigenic drift and antigenic shift in the influenza virus is incorrectly matched? A) Antigenic shift: Often leads to viral strains with new features such as increased infectivity or expanded host range. B) Antigenic drift: Spontaneous mutation leads to a minor change in HA or NA spikes. C) Antigenic drift: A host vaccinated against an influenza strain before antigenic drift may lack effective immunity and be susceptible to infection. D) Antigenic shift: May result in a pandemic outbreak due to widespread lack of immunity. E) Antigenic drift: Often involves reassortment of viral strains in an animal host followed by a "species jump" to humans.

13)

14) Which property is not used to classify viruses? A) type of nucleic acid present B) capsid symmetry C) genome architecture D) presence or absence of an envelope E) tissue types infected

14)

15) Which viral family and representative disease contains single-stranded+ RNA and reverse transcriptase? A) Retroviridae (AIDS) B) Rhabdoviridae (rabies) C) Filoviridae (Ebola) D) Orthomyxoviridae (influenza) E) Paramyxoviridae (measles)

15)

16) All the following are DNA viruses except A) Hepadnaviridae. B) Papillomaviridae. C) Adenoviridae. D) Herpeseviridae. E) Picornaviridae.

16)

17) Viruses which infect many different tissues types are said to have a(n) A) narrow tropism. B) indeterminate host range. C) narrow host range. D) broad host range. E) broad tropism.

17)

18) Which suffix denotes the "order" level of classification for viruses? A) - virion B) - viridae C) - virales D) - virus E) Viruses are not classified to the "order" level.

18)

19) The key event that occurs during lysogenic replication of bacteriophage that does not occur during lytic replication is A) release of mature viral particles by lysis of the bacterial cell. B) assembly of new phage by packing viral genomes into capsids. C) integration of the phage DNA into the host cell DNA. D) penetration of the phage DNA into the host cell. E) attachment of the phage to specific proteins in the bacterial cell.

19)

20) During lytic replication of bacteriophage, which process uses factors from the host cell, rather than coded by the viral genome? A) proteins to build new phage particles B) lysozyme to rupture the host cell C) DNAases to break up the host cell genome D) proteins to copy the viral genome E) enzymes which transcribe and translate viral genes

20)

21) Phage conversion occurs when A) prophage confer new pathogenic properties on bacterial cells. B) bacteriophage are used clinically to treat bacterial infections. C) a host cell is infected by a bacteriophage. D) prophase excise themselves and resume lytic replication when the host cell is stressed. E) bacteriophage are released from the host cell.

21)

22) Which stage of animal virus replication may be blocked by a drug that binds with the viral spike? A) uncoating B) attachment C) assembly D) replication E) penetration

22)

23) HIV, the virus which causes AIDS, interacts with two receptors on the host cell membrane: CD4 and CCR5. A small percentage of individuals have a genetic mutation which causes their cells to lack CCR5. These individuals will never develop AIDS nor are they able to pass HIV on to others. Which part of viral replication is being blocked by the lack of a receptor? A) The virus components cannot be assembled into new virions. B) The host cell enzymes are unable to replicate the HIV genome. C) HIV cannot attach to the host cell without the proper membrane receptor. D) Newly assembled virions cannot be released from the host cell. E) Endocytosis is being prevented.

23)

24) Which stage of viral replication is shown?

24)

A) penetration via endocytosis B) release by budding C) attachment D) penetration via membrane fusion E) release by lysis

25) Which stage of animal virus replication will not be different between naked viruses and enveloped viruses? A) release B) uncoating C) replication D) assembly E) penetration

25)

26) Which statement is not true about chronic persistent viral infections? A) May involve periods of flare-up where the virus is actively replicating alternating with periods of dormancy. B) May involve integration of the virus into the host cell DNA to form a provirus. C) Small numbers of virions may be produced and released from host cells during the quiet periods. D) A period of quiet infection where the host is asymptomatic is followed by a period of active viral replication. E) The immune system fails to clear the infection.

26)

27) Which type of viral infection is demonstrated by the graph?

27)

A) acute persistent B) lysogenic C) acute non-persistent D) chronic persistent E) latent persistent 28) Oncogenic viruses A) are never RNA viruses. B) suppress the host immune system. C) always integrate into the host cell DNA. D) increase host cell responsiveness to death signals. E) stimulate uncontrolled host cell division.

28)

29) Which is not a cancer linked to a specific virus? A) adult T-cell leukemia B) liver cancer C) cervical cancer D) skin cancer E) Kaposi sarcoma

29)

30) Animal viruses can be grown in all of the following except A) E. coli cells. B) live animal hosts. C) embryonated eggs. D) HeLa cells. E) tissue culture.

30)

31) When mixed with their host bacterium and plated on solid agar, lytic phage will form clear areas in bacterial growth. What are these clear areas called?

31)

A) plaques B) titers C) halos D) zones of inhibition E) assays 32) One ml of a liquid suspension of bacteriophage is mixed with its host bacteria and plated. After incubation, the plate is completely clear. What is the probable explanation? A) The bacteria mutated and could no longer be infected by this phage. B) The bacteriophage culture was dead. C) The phage concentration was too low to infect many bacterial cells. D) The phage concentration was so high that all the host bacterial cells were killed. E) The bacteriophage doesn't grow on the type of agar used.

32)

33) What does the plaque assay determine? A) if a given drug will be useful in treating a given viral infection B) if the virus can grow in a live animal host C) number of bacteriophage in a sample D) if the phage is a lysogenic phage E) type of bacteriophage in a sample

33)

34) Which of the following tests works by detecting viral nucleic acid? A) ELISA B) Agglutination with beads coated with antibodies to the virus C) PCR D) Agglutination with beads coated with viral antigens E) Agglutination with beads coated with either antibodies or antigens

34)

35) An individual uses an in-home test kit one week after engaging in high-risk behavior for HIV infection. The test kit uses a saliva sample that is mailed to a lab where an agglutination test to detected HIV antibodies is run. The results come back negative for HIV. What should the patient consider regarding these test results? A) One week may not be enough time for HIV antibodies to be detected. B) Agglutination tests will not detect viruses if the infection is latent. C) Agglutination tests will not detect viruses if the infection is latent, nor are they appropriate for testing samples of body fluids. D) An ELISA test is needed to detect the presence of HIV nucleic acid. E) Agglutination tests are not appropriate for testing samples of body fluids.

35)

36) Challenges in developing effective antiviral drugs with minimal side effects to the patient include A) viruses have many more chemically distinct targets than living pathogens. B) viruses use the cell's own machinery and metabolism for replication. C) drugs can be easily delivered to reach viruses within host cells. D) only the attachment stage of the viral life cycle is a suitable target for antiviral drug action. E) the immune system is rarely successful in ending viral infections so there is no natural model to work from.

36)

37) Which of the following antiviral drug categories is incorrectly matched with its description? A) Antisense antivirals: Short sequences of nucleotides that are complementary to viral RNA B) Nucleotide reverse transcriptase inhibitors: Target retroviruses C) Proteases: Target protein-cutting enzymes which make mature virons D) Nucleoside analogs: Mimic normal nucleotides interfering with nucleic acid replication E) Interferons: Used for postexposure prophylaxis

37)

38) Prions are A) diagnosed with a simple blood test. B) associated with many tissue types. C) misfolded proteins which can cause normal versions to also misfold. D) infectious nucleic acids. E) living, acellular entities.

38)

39) Which of the following prion diseases may be acquired by eating beef contaminated with a cattle prion? A) Gerstmann-Straussler-Schienker syndrome B) sporadic CJD C) variant CJD D) iatrogenic CJD E) inherited CJD

39)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 40) Both viruses and prokaryotes reproduce by binary fission.

40)

41) The shape of a virus may be determined by either its capsid or its envelope.

41)

42) The number of species that a specific virus infects is called its host range while the types of tissues that the virus infects is called tropism.

42)

43) Like bacteriophage, when an animal cell virus enters a host cell, only the genome enters while the capsid remains outside the cell.

43)

44) Naked viruses usually exit the animal host cell by budding while enveloped viruses exit by lysis.

44)

45) All persistent viral infections occur when the virus integrates into the host cell DNA to form a provirus.

45)

46) Both agglutination and ELISA procedures may be used to detect the presences of either viral antigen or the patient's antibodies to a virus.

46)

47) Antiviral drugs exist that target all stages of viral replication except the production of viral nucleic acids.

47)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 48) Use the concepts of antigenic drift and antigenic shift to describe why influenza causes both "routine" seasonal outbreaks as well as to periodically cause more serious global outbreaks, or pandemics. 49) Describe the lytic and lysogenic bacteriophage replication cycles.

50) Select three points in the viral replication process and describe how an antiviral drug may be used to target that Provide the name of one drug or drug family that targets the steps you chose.

Answer Key Testname: UNTITLED20

1) B 2) C 3) B 4) E 5) C 6) E 7) C 8) A 9) D 10) B 11) D 12) B 13) E 14) E 15) A 16) E 17) E 18) C 19) C 20) E 21) A 22) B 23) C 24) B 25) C 26) A 27) E 28) E 29) D 30) A 31) A 32) D 33) C 34) C 35) A 36) B 37) E 38) C 39) C 40) FALSE 41) FALSE 42) TRUE 43) FALSE 44) FALSE 45) FALSE 46) TRUE 47) FALSE

Answer Key Testname: UNTITLED20

48) Influenza has two spikes, HA and NA, which allow the virus to attach to and escape cells. During infection, the immune system generates antibodies which will neutralize that influenza pathogen during a current or subsequent infection. Because influenza is an RNA virus, it undergoes frequent mutations which result in minor changes in the spikes. These spikes may be different enough to evade quick detection by the previously-generated antibodies. This is antigenic drift, and is why a new influenza vaccine must be formulated each year and why a portion of the population is unprotected, leading to seasonal outbreaks. Antigenic shift occurs when the virus undergoes a major genetic reassortment that dramatically changes the spikes. These "new" viruses may have increased infectivity or expanded host range, and are also unlikely to be recognized by current vaccines. Most of the population will have no residual immunity to this new strain, so the virus spreads rapidly and causes serious illness. 49) Both lytic and lysogenic bacteriophage begin a replication cycle when contact is made with a suitable host bacterium. During attachment, components of the phage capsid bind to a specific molecule on the host bacterium. The bacteriophage genetic material is then injected into the bacterium, leaving the capsid on the outside. At this point, a lytic phage infection will result in the use of host cell factors to transcribe and translate viral genes. DNAases produced by the virus will break up the bacterial genome, and the viral genome is replicated. Once many copies of the viral genetic material and capsid proteins are produced, new phages are assembled by inserting the genome into the capsid. To release the bacteriophage, an enzyme called lysozyme breaks down the host cell wall. During a lysogenic infection, the phage DNA is not immediately replicated, transcribed, and translated, but instead, inserts itself into the bacterial genome. The phage DNA remains as a prophage and is copied whenever the host cell replicates its genome. The prophage is passed down the bacterium's daughter cells through binary fission. If the bacterial cell is ever under stress, the prophage may excise itself and begin a replication cycle identical to the remaining steps of the lytic cycle. 50) Attachment may be blocked by antibodies or other molecules which prevent the virus from interacting with the host cel receptor. Enfuviritide*, Docosanol*, Palivizumab, HRIG. Penetration may be blocked by interfering with membrane fusion or endocytosis. Interferon-alpha. Uncoating may be blocked to prevent access to the virus nucleic acid for replication. Amantadine, Rimantadine, Vapen Replication may be blocked to prevent the viral nucleic acids from being replication or transcribed, or by blocking rever transcription in retroviruses. Nucleoside reverse transcriptase inhibitors (AZT), nucleoside/nucleotide analogs (ribaviri antisense antivirals (Vitravene). Assembly can be blocked to prevent mature virions from being put together. Protease inhibitors, interferons. Release can be blocked to prevent viral budding from the host cell membrane. Oseltamivir (Tamiflu), zanamivir (Relen

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following terms refers to bacteria reproducing asexually by dividing the cell in half and resulting in two daughter cells? A) sporulation B) hypha C) budding D) conidia E) binary fission

2) Mycobacterium tuberculosis are grown for 80 hours. During that time, they go through four generations of growth. What is the generation time? A) 60 minutes B) 10 hours C) 40 hours D) 20 hours E) 20 minutes

3) In which growth phase do bacteria grow exponentially? A) acculturation phase B) stationary phase C) habituation phase D) lag phase E) log phase

4) In which growth phase do bacteria adjust to their environment and grow little, if any? A) acculturation phase B) lag phase C) stationary phase D) log phase E) habituation phase

5) In which growth phase do bacteria produce antibiotics and endospores? A) log phase B) stationary phase C) death phase D) lag phase E) acculturation phase

6) Which of the following is not an environmental factor that would affect the growth of E. coli? A) temperature B) generation time of E. coli C) availability of nutrients D) concentration of other bacteria E) antibiotics produced from other bacterial species

7) Which term represents the temperature that bacteria grow the fastest at? A) optimal B) hospitable C) minimum D) human body temperature E) maximum

8) Which of the following types of organisms is associated with foodborne illness? A) extreme thermophiles B) thermophiles C) psychrotrophs D) mesophiles E) psychrophiles

9) Which temperature group are most pathogens associated with? A) psychrophiles B) extreme thermophiles C) psychrotrophs D) thermophiles E) mesophiles

10) Extreme thermophiles that live near thermal vents must have all of the following adaptations except A) they must also be barophiles. B) proteins that resist thermal denaturing. C) plasma membrane lipids that are highly unsaturated. D) specialized chaperone proteins. E) plasma membrane lipids that are highly branched and saturated.

10)

11) Which of the following pH classifications would be able to grow in a pickle jar with vinegar? A) alkaliphiles B) acidophiles C) neutralophiles D) psychrophiles E) barophiles

11)

12) Which of the following pH classifications make up most of the pathogens we know today? A) acidophiles B) barophiles C) alkaliphiles D) psychrophiles E) neutralophiles

12)

13) Which of the following methods do alkaliphiles use to survive in their environments? A) enrich their plasma membrane with basic compounds to attract OH- ions to their cell surface

13)

B) use proton pumps to export excess protons from the cytoplasm C) use plasma membrane lipids that are highly branched and saturated D) enrich their plasma membrane with acidic compounds to attract H+ ions to their cell surface E) build special monolayer plasma membranes

14) Which of the following terms refers to microbes that thrive in high-salt environments? A) psychrophiles B) barophiles C) acidophiles D) neutralophiles E) halophiles

14)

15) How do halophiles combat osmotic stress? A) They build special monolayer plasma membranes. B) They use plasma membrane lipids that are highly branched and saturated. C) They use proton pumps to export excess protons from the cytoplasm. D) They enrich their plasma membrane with basic compounds to attract OH- ions to their cell

15)

surface. E) They keep a high concentration of organic materials and ions in their cytoplasm. 16) Staphylococcus aureus tolerates higher solute concentrations but doesn't grow especially well in them. Therefore, it is called a A) mesophilic neutralophile. B) halo-psychrophile. C) halo-alkaliphile. D) halo-thermophile. E) facultative halophile.

16)

17) Which group of microbes prefers using oxygen but can survive without it? A) microaerophile B) facultative anaerobe C) obligate aerobe D) aerotolerant anaerobe E) obligate anaerobe

17)

18) Microbes that primarily infect the lungs are likely to be classified as which of the following? A) obligate anaerobe B) obligate aerobe C) facultative anaerobe D) microaerophile E) aerotolerant anaerobe

18)

19) Nutrients that a cell needs to build new cells and make up a bulk of a cell's dry weight are called A) micronutrients. B) tiny nutrients. C) small nutrients. D) trace nutrients. E) essential nutrients.

19)

20) The necessary substances that a cell can't make on its own are called A) vitamins. B) growth factors. C) carbohydrates. D) amino acids. E) nitrogenous bases.

20)

21) Which type of organism gets energy from breaking down nutrients and uses CO2 as a carbon

21)

source? A) photoheterotroph B) photoautotroph C) lithotroph D) chemoautotroph E) chemoheterotroph 22) When would a microbiologist want to use broth media? A) when testing for motility B) when growing large batches of microbes C) when observing specific culture characteristics D) when isolating colonies E) when performing the streak plate isolation technique

22)

23) Which type of organism would a microbiologist grow on defined media? A) fastidious organisms B) pathogens from clinical samples C) certain autotrophs D) a broad collection of heterotrophs E) organisms with complex growth requirements

23)

24) Which type of media has ingredients that foster the growth of certain bacteria while suppressing the growth of others? A) differential B) defined C) complex D) synthetic E) selective

24)

25) When would a microbiologist use thioglycolate? A) when storing selective plates B) when making defined media C) when storing plates anaerobically D) when storing differential plates E) when making complex media

25)

26) Which of the following could result in the wrong patient diagnosis and improper treatment? A) using a cotton tip swap to collect a suspected pathogen B) quickly sealing samples in containers C) proper hand washing before and after specimen collection D) carefully sampling only the site in question without touching other body structures or surface sites E) wearing gloves

26)

27) What is the purpose of the streak plate technique? A) to identify the correct concentration of nutrients needed for optimal bacterial growth B) to ascertain the age of a particular culture C) to identify the best temperature for growing a particular microbe D) to determine the concentration of a microbial sample E) to obtain a pure culture from a mixed or unknown source

27)

28) Which of the following cell-counting methods is capable of differentiating between living and dead cells? A) microscopic count B) dry weight C) flow cytometer D) turbidity measurement E) Coulter counter

28)

29) Which of the following is an indirect cell-counting method? A) flow cytometer B) microscopic count C) viable plate count D) Coulter counter E) turbidity measurement

29)

30) A chemical used to control microbial growth on inanimate objects is called a(n) A) antiseptic. B) disinfectant. C) microbiostatic. D) antibacterial agent. E) microbiocidal.

30)

31) The minimum temperature needed to kill all microbes in a sample within ten minutes is called the A) thermal death point. B) decimal reduction time. C) thermal death time. D) critical death time. E) essential reduction point.

31)

32) Which of the following methods would surgical staff use to disinfect surfaces in operating rooms? A) x-ray radiation B) ionizing radiation C) autoclaving D) non-ionizing radiation E) gamma ray radiation

32)

33) Which of the following factors does not affect the efficiency of a germicide? A) how the object is used B) the number of microbes to be killed C) what infectious agents are most likely present D) the presence of excessive organic substances like blood, soil, or fecal matter E) the presence of excessive inorganic substances like minerals and salts in hard water

33)

34) Low-level disinfectants are sufficient to remove microbes from which of the following equipment tiers? A) non-vital B) nonessential C) semicritical D) noncritical E) vital

34)

35) Which of the following microbes is not correctly matched to an acceptable control method? A) Mycobacteria: hydrogen peroxide B) Prions: chlorine treatment C) Enveloped virus: glutaraldehyde-based detergents D) Protozoan: boiling water E) Endospore: autoclaving

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) Bacterial spore formation is a type of sexual reproduction.

36)

37) In the death phase of a closed pure batch system a small number of the cells survive by adapting to the new waste-filled environment and by feeding off dead cells.

37)

38) Many microbes have evolved ways to detoxify reactive oxygen species so that they can safely use oxygen in their metabolism.

38)

39) Chemoautotrophs use an inorganic carbon source.

39)

40) The Simmons citrate test and triple sugar iron (TSI) media are common examples of slants.

40)

41) The pour plate method is capable of detecting an exact cell number in the plated sample.

41)

42) Disinfectants are applied to living tissue such as skin.

42)

43) Phenols are commonly used in hospitals to sterilize critical equipment.

43)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 44) Name three differences between how microbes grow in a closed pure batch system as compared to in nature. 45) Name one benefit and one challenge to using genetic methods to identify microbes. 46) What are two benefits to a germicide that quickly evaporates compared to a germicide that leaves a residue behind?

Answer Key Testname: UNTITLED21

1) E 2) D 3) E 4) B 5) B 6) B 7) A 8) C 9) E 10) C 11) B 12) E 13) D 14) E 15) E 16) E 17) B 18) B 19) E 20) B 21) D 22) B 23) C 24) E 25) C 26) A 27) E 28) C 29) E 30) B 31) A 32) D 33) A 34) D 35) B 36) FALSE 37) TRUE 38) TRUE 39) FALSE 40) TRUE 41) FALSE 42) FALSE 43) FALSE 44) Microbes are unlikely to experience a phase of rapid exponential growth in nature because the growth conditions for nutrients, pH level, and temperature will not be optimized. When growing in nature, it is uncommon to have a pure culture and as a result of that bacteria will compete for nutrients and release different antibiotics in order to horde vital resources. Furthermore, when growing in nature, bacteria are likely to be growing as a biofilm which can significantly change the metabolism of the bacteria as well as several other features.

Answer Key Testname: UNTITLED21

45) Genetic methods are good at identifying microbes because they can be quick. However, they rely on the use of previously designed probes, which means that you already have to have an idea about what you are looking for. A negative result only tells you, you don't have that kind of microbe, it doesn't tell you which kind you do have or even if you have anything at all. 46) A germicide that quickly evaporates is capable of working to kill microbes and then leaves no trace behind. This reduces the chances that microbes would be able to evolve an immunity to the germicide because of their limited contact with the chemical. A second benefit would be that there is no rinse step required before the next patient comes into contact with the equipment.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The term includes both the chemical reactions that organisms use to break down substances to release energy, as well as the reactions that use released energy to build new substances. A) metabolism B) anabolism C) oxidation-reduction D) biosynthesis E) catabolism

2) Anabolic reactions A) are endergonic and involve dehydration synthesis. B) involve dehydration synthesis. C) involve breaking down larger molecules into smaller molecules. D) are endergonic. E) are endergonic and involve breaking down larger molecules into smaller molecules.

3) Catabolic reactions A) are endergonic and are hydrolytic. B) are endergonic. C) involve breaking down larger molecules into smaller molecules. D) are hydrolytic and involve breaking down larger molecules into smaller molecules. E) are hydrolytic.

4) Catabolic and anabolic reactions depend upon each other, as evidenced by which of the following statements? A) Anabolic reactions split bigger molecules into smaller components, which are in turn used by catabolic reactions to build more complex molecules. B) Catabolic reactions split bigger molecules into smaller components which are used by anabolic reactions to build more complex molecules AND catabolic reactions release energy which is used by anabolic reactions. C) Catabolic reactions release energy which is used by anabolic reactions D) Anabolic reactions split bigger molecules into smaller components, which are in turn used by catabolic reactions to build more complex molecules AND catabolic reactions release energy which is used by anabolic reactions. E) Catabolic reactions split bigger molecules into smaller components which are used by anabolic reactions to build more complex molecules.

5) In the typical ATP-ADP cycle, which part of the ATP molecule is removed when energy is released and added back when energy is stored? A) adenine B) the terminal two phosphate groups C) ribose D) the terminal phosphate group E) all three phosphate groups

6) What is the relationship between the ATP-ADP cycle and catabolic and anabolic reactions? A) Energy released from catabolic reactions is used to break ATP down to ADP. Then the energy needed for anabolic reactions is released by to recharging ADP back to ATP. B) Catabolic reactions require energy, which is provided by anabolic reactions. ADP is recharged to ATP by energy from anabolic reactions. C) Energy released from catabolic reactions is used to recharge ADP back to ATP. Then the energy needed for anabolic reactions is released by breaking ATP down to ADP. D) Energy released from anabolic reactions is used to recharge ADP back to ATP. Then the energy needed for catabolic reactions is released by breaking ATP down to ADP. E) There is no relationship between the ATP-ADP cycle and catabolic and anabolic reactions.

7) Enzymes are necessary for cells because A) enzymes slow down chemical reactions that would otherwise occur too quickly to facilitate life. B) enzymes allow chemical reactions to occur under physiological conditions and within a time frame conducive to life. C) enzymes allow chemical reactions to occur quickly enough to facilitate life. D) enzymes allow chemical reactions to occur under physiological conditions. E) enzymes allow chemical reactions to take place that would otherwise be impossible.

8) Which structural and functional feature(s) listed are key to an enzyme's activity? A) consumed each time a reaction takes place B) consists of a three-dimensional protein structure that interacts with a substrate in a fixed "lock-and-key" model C) consumed each time a reaction takes place and consists of a three-dimensional protein structure that interacts with a substrate in a fixed "lock-and-key" model D) consumed each time a reaction takes place and contains an active site where the enzyme can interact with a specific substrate E) contains an active site where the enzyme can interact with a specific substrate

9) Which facts about enzymes are not visualized in this figure?

A) Enzymes stabilize the transition state of the reaction that point where the reactants are becoming the products. B) Specific products are generated. C) A cofactor is often required for enzyme activity. D) A substrate binds to an enzyme at the active site as described by the "induced-fit" model 3

E) Enzymes are not consumed or permanently changed in a reaction. 10) Enzymes can lower the activation energy of a chemical reaction by A) stabilizing the transition state. B) raising the temperature so that reactants collide more forcefully. C) properly positioning reactants and raising the temperature so that reactants collide more forcefully. D) properly positioning reactants. E) properly positioning reactants and stabilizing the transition state.

10)

11) Which coenzyme is incorrectly matched with its function? A) Coenzyme A: Metabolism of pyruvic acid and lipids B) NAD+ /NADP+: Electron transfers

11)

C) Cobalamin: Transfer of CO2 groups D) THF / DHF: Make purines and pyrimidines E) FAD / FMN: Electron transfers 12) Ribozymes are enzymes which A) are made of RNA and work on RNA substrates. B) are made of RNA. C) may have medical applications as antiviral therapies. D) are made of RNA, work on RNA, and may have medical applications as antiviral therapies. E) work on RNA substrates.

12)

13) Which of the following factors may influence an enzyme's activity by altering its three-dimensional structure? A) competitive inhibitor B) temperature C) pH, temperature, and competitive inhibitor D) pH E) pH and temperature only

13)

14) The graph shows enzyme activity as a function of temperature for a mesophilic microbe. How woul predict that the graph would change if the organism was a psychrophile (an organism that thrives a temperatures)?

A) The graph would be a horizontal straight line. B) The graph would be similar, but would be shifted toward the right. C) The graph would be wider (extended further both left and right) but the peak would be lower. D) The graph would be similar, but would be shifted toward the left. E) The graph would not peak then drop off, but would continue rising indefinitely.

14)

15) The figure shows which process?

15)

A) either allosteric inhibition, competitive inhibition, or non-competitive inhibition B) allosteric inhibition C) allosteric activation D) non-competitive inhibition E) competitive inhibition 16) Oxidation of nutrients by cells results in A) a requirement of energy which can be obtained by converting ATP to ADP. B) a release of energy, which is released by converting ATP to ADP. C) a release of energy, which can be used to recharge ADP to ATP. D) a requirement for energy which can be used to recharge ADP to ATP. E) either a release or a requirement for energy depending on what type of nutrient is available.

16)

17) When electrons are removed from nutrients via an oxidation reaction, the coupled reduction reaction may be A) NADH → NAD+.

17)

B) NAD+ → NADH. C) FAD → FADH2. D) either FAD → FADH2 or NAD+ → NADH. E) either NAD+ → NADH or NADH → NAD+. 18) Which phosphorylation mechanism for recharging ADP to ATP is incorrectly matched with its description? A) Substrate-level phosphorylation: A phosphate is transferred to ADP from a high-energy substrate after passing through an electron transport chain. B) Photophosphorylation: Passes electrons energized by solar energy through an electron transport chain C) Oxidative Phosphorylation: Passes electrons stripped from nutrients through an electron transport chain D) The descriptions for oxidative phosphorylation and photophosphorylation are incorrectly matched. E) The descriptions for oxidative phosphorylation, photophosphorylation, and substrate-level phosphorylation are incorrectly matched.

18)

19) Which of the following does not describe cellular respiration? A) may include multiple pathways including glycolysis, an intermediate step, the Krebs cycle and fermentation B) may occur in both prokaryotic and eukaryotic cells C) involves a transfer of energy into the bonds of ATP D) occurs in part in the mitochondria of eukaryotic cells E) collection of reactions that extract energy from food using redox reactions

19)

20) Refer to the numbered steps in the figure when answering the question. Which step shows an energ investment in the form of ATP?

A) steps 1 and 3 B) steps 1 and 10 C) steps 3 and 7 D) steps 7 and 10 E) steps 1, 3, 7, and 10

20)

21) Refer to the numbered steps in the figure when answering the question. Which step is a redox reacti

A) step 1

B) step 3

C) step 4

22) What are the products made during glycolysis? A) 4 ATP (net gain of 2) and 2 NADH and 2 pyruvic acid B) 2 pyruvic acid C) 4 ATP (net gain of 2) D) 4 ATP (net gain of 2) and 2 NADH E) 2 NADH

D) step 6

21)

E) step 9 22)

23) Which molecule is the product of the intermediate step which is a direct input into the Krebs cycle? A) NADH B) carbon dioxide C) pyruvic acid D) ATP E) acetyl CoA

23)

24) Refer to the numbered steps in the figure when answering the question. Two carbons in the form of acetyl-CoA enter the Krebs cycle by joining with oxaloacetic acid, a 4-carbon molecule. During which step does carbon leave the Krebs cycle in the form of CO2?

24)

A) step 1 B) step 3 C) step 4 D) step 1 and step 3 and step 4 E) step 3 and step 4 10

25) Sequence the following events as they occur at the electron transport chain. I. Protons accumulate on one side of the membrane to form a proton motive force. II. The coenzymes NADH and FADH2 drop off electrons to the carriers in the respiratory chain.

25)

III. Protons flow through ATP synthase which captures the energy of the flowing protons and uses i recharge ADP to ATP. IV. Electrons moving through the chain release energy to pump proteins across the membrane wher carrier proteins are found. A) II → IV → I → III B) I → II → III → IV C) III → II → IV → I D) I → III → IV → II E) II → I → IV → III 26) Which of the following statements correctly describes what happens during chemiosmosis? A) The energy of protons flowing through the ATP synthase enzyme powers the recharge of ADP to ATP. B) Protons are added directly to ADP to recharge it to ATP. C) Protons flow through the ATP synthase enzyme from the side of the membrane where they are lower in concentration to the side where they are higher in concentration. D) Only electrons from the reduced carrier NADH are deliver to the electron transport chain; the reduce carrier FADH2 takes its electrons elsewhere.

26)

E) The purpose is to generate water from oxygen. 27) Cyanide is a poison which prevents the last carrier in the electron transport chain (cytochrome C oxidase) from transferring the electron to the final electron acceptor. Which of the following would not be a consequence of exposure to this poison? A) Protons would no longer be pumped outside the membrane. B) ADP would no longer be recharged to form ATP. C) Movement of electrons through the chain would stop. D) Carbon dioxide would continue to be generated. E) Glycolysis, the intermediate reaction, and the Krebs cycle would stop as the cell would run out of the necessary oxidized coenzymes NAD+ and FAD.

27)

28) Consider this summarized chemical reaction for aerobic cellular respiration:

28)

C6H12O6 + 6 O2 + 38 ADP + 38 PO32- → 6 CO2 + 6 H2O + 38 ATP What would be different in a summarized chemical reaction for anaerobic cellular respiration? A) The numbers of ADP, PO32-, and ATP used / generated would be different. B) The water would be replaced by a different reduced product. C) The oxygen would be replaced by a different inorganic compound. D) The oxygen would be replaced by a different inorganic compound and the water would be replaced by a different reduced product. E) The numbers of ADP, PO32-, and ATP used / generated would be different and the oxygen would be replaced by a different inorganic compound and the water would be replaced by a different reduced product.

29) Which is the key difference between aerobic and anaerobic respiratory chains? A) Aerobic respiratory chains always use oxygen as the final electron acceptor while anaerobic respiratory chains may use a variety of inorganic substances other than oxygen as the final electron acceptor. B) Aerobic respiratory chains accept electrons from both NADH and FADH2 while anaerobic

29)

chains only accept electrons from FADH2. C) Aerobic respiratory chains that accept electrons depend on membrane-associated electron carrier molecules that carry out redox reactions while anaerobic chains use cytoplasm-associated molecules that carry out redox reactions. D) Aerobic respiratory chains are found in prokaryotic cells only while anaerobic chains are found in eukaryotic cells only. E) Aerobic respiratory chains are organized so that electrons are passing from a higher to lower energy state while anaerobic chains are organized so that electrons are passing from a lower to a higher energy state. 30) Which statement is not true about the pentose phosphate pathway? A) It diverts glucose-6-phosphate from glycolysis to synthesize 5-carbon sugars needed for nucleotides. B) It allows cellular respiration to occur without the need for oxygen. C) It converts 5-carbon sugars into 3- and 6-carbon for use in glycolysis. D) It produces the coenzyme NADPH needed for anabolic pathways. E) It can be used in part by photosynthetic cells to build glucose from carbon dioxide.

30)

31) The main goal of fermentation is to sustain ATP production by glycolysis. This is accomplished by A) diverting glycolysis intermediates into the pentose phosphate pathway. B) producing acids which lower cellular pH to promote more efficient ATP recharge. C) passing the electrons on NADH to pyruvic acid, regenerating NAD+ so glycolysis can

31)

continue. D) enables the cell to use its respiratory chain without oxygen being available. E) producing acids and alcohols which the microorganism can use as an alternative nutrient source when glucose is not available. 32) Which of the following pathways are operational in a cell growing via fermentation? A) intermediate step B) glycolysis C) glycolysis, intermediate step, and the Krebs cycle D) Krebs cycle E) glycolysis and intermediate step only

32)

33) Of the following fermentation pathways, which can be carried out by human muscle cells? A) butanediol B) lactic acid: heterolactic C) alcoholic D) lactic acid: homolactic E) mixed acid

33)

34) In order to harvest energy from polysaccharides, lipids or proteins, cells must use to break down these large macromolecules extracellularly before bringing them into the cell. A) deamination B) beta-oxidation C) exoenzymes D) Entner-Doudoroff pathway E) glycogenesis

34)

35) Gluconeogenesis A) is building glucose from non-sugar starting materials. B) can be accomplished by funneling intermediates from glycolysis, the Krebs cycle, and lipid or protein catabolism. C) is building glucose from non-sugar starting materials and can be accomplished by funneling intermediates from glycolysis, the Krebs cycle, and lipid or protein catabolism. D) is building glucose from non-sugar starting materials and can be accomplished by funneling intermediates from glycolysis, the Krebs cycle, and lipid or protein catabolism and an example of biosynthesis. E) is an example of biosynthesis.

35)

36) The intermediate(s) needed to synthesize lipids from sugar catabolism is (are) A) dihydroxyacetone phosphate (DHAP). B) acetyl CoA and dihydroxyacetone phosphate (DHAP). C) citric acid. D) acetyl CoA. E) citric acid and dihydroxyacetone phosphate (DHAP).

36)

37) Many strains of E. coli are able to grow on minimal media which consists only of a single sugar, usually glucose, and inorganic salts to provide nitrogen, sulfur, phosphorous and trace nutrients. What does this tell you about E. coli's biosynthetic capabilities? A) E. coli will be unable to perform amination. B) All amino acids are "essential" to E. coli. C) E. coli will be unable to build the peptidoglycan it needs for its cell wall. D) E. coli will use salvage pathways to make nucleotides. E) E. coli can funnel intermediates from glycolysis, the intermediate step, and the Krebs cycle to synthesize amino acids, fatty acids, glycerol, and nucleotides.

37)

38) One of the ways that cells balance anabolism and catabolism is to A) use feedback inhibition to shut down a pathway that is not needed and use separate coenzymes such as NAD+ vs. NADP+ for catabolic vs. anabolic pathways.

38)

B) use the same enzyme to run a reaction in both the catabolic and anabolic direction. C) use feedback inhibition to shut down a pathway that is not needed. D) use the same enzyme to run a reaction in both the catabolic and anabolic direction and use feedback inhibition to shut down a pathway that is not needed. E) use separate coenzymes such as NAD+ vs. NADP+ for catabolic vs. anabolic pathways. 39) A pathway that functions simultaneously in both anabolism and catabolism is termed A) biosynthetic. B) cyclic. C) amphibolic. D) allosteric. E) redox. 13

39)

40) Which is not one of the categories used to classify an organism based on its nutrition? A) initial source of electrons for reduction reactions B) source of energy for making ATP C) ability to fix carbon D) ability to run either catabolic or anabolic pathways E) source of energy for making ATP and ability to run either catabolic or anabolic pathways

40)

41) Bacteria that live in deep ocean volcanic vents form the base of an ecosystem that exists without light. They obtain electrons from hydrogen sulfide compounds dissolved in the vent water, and synthesize sugars from carbon, hydrogen, and oxygen. The bacteria would be classified as A) chemolithoautotrophs. B) chemoorganoheterotrophs. C) photolithoautotrophs. D) photoorganoheterotrophs. E) chemolithoheterotrophs.

41)

42) Biochemical tests are useful to microbiology because A) they can be used to identify microbes. B) they can be used to identify microbes and to identify potential pathogens in clinical samples. C) they can be used to identify microbes and to identify potential pathogens in clinical samples and they can be used to detect metabolic end-products, intermediates, or particular enzymes. D) they can be used to detect metabolic end-products, intermediates, or particular enzymes. E) they can be used to identify potential pathogens in clinical samples.

42)

43) Which category of biochemical tests is incorrectly matched with its description? A) Fermentation tests: Detects various fermentation end-products or specific pathways B) Rapid identification techniques: Provides a semi-automated process of running multiple types of tests with a single inoculation C) Oxidase and catalase tests: Identifies the presence of enzymes related to anaerobic respiratory chains D) Exoenzyme tests: Detect enzymes involved in extra-cellular breakdown of macromolecules E) Amino acid catabolism tests: Detect specific enzymes involved in catabolism of amino acids

43)

44) Besides biochemical tests, which techniques are also useful for identifying a bacterial specimen? A) microscopy B) observation of general culture characteristics C) molecular genetics techniques D) microscopy and molecular genetics techniques and observation of general culture characteristics E) microscopy and observation of general culture characteristics

44)

45) What is the advantage of a rapid identification tool such as the API system? A) can often be read using an automated reader B) allows a high volume of samples to be processed quickly and reliably and can often be read using an automated reader C) allows a high volume of samples to be processed quickly and reliably and can be inoculated with a mixed or unpurified culture D) can be inoculated with a mixed or unpurified culture E) allows a high volume of samples to be processed quickly and reliably

45)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 46) Catabolic reactions are hydrolytic and exergonic while anabolic reactions are biosynthetic and endergonic.

46)

47) Ribozymes are enzymes which are made of protein but only work on RNA molecules as substrates.

47)

48) Cells harvest energy from nutrients by stripping electrons from them. In other words, the nutrients are oxidized.

48)

49) By the end of the Krebs cycle, every carbon originally in glucose is converted into carbon dioxide.

49)

50) The main energy benefit of the Krebs cycle is the mass production of both ATP and the reduced factors NADH and FADH2.

50)

51) In chemiosmosis, protons funnel through ATP synthase from an area where they are more concentrated to an area where they are less concentrated.

51)

52) The Entner-Doudoroff pathway is a less efficient alternative to glycolysis which likely evolved early in the history of life to catabolize glucose.

52)

53) A bacterial culture which is growing under conditions that only allow for fermentation will grow at the same rate as a culture of the same species growing under conditions which allow for aerobic cellular respiration, all other conditions being identical.

53)

54) Generally, purines and pyrimidines are not synthesized de novo but rather obtained through salvage pathways to recycle them from food because de novo synthesis has a high energy cost.

54)

55) Usually, a single biochemical test is all that is needed to identify an unknown microbial sample.

55)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 56) Describe or diagram the relationship between catabolic pathways, anabolic pathways and the ATP-ADP cycle. Include in your answer an explanation of the role each of these plays in the metabolism of a cell. 57) Describe two factors which may increase enzyme activity and two factors which may decrease enzyme activity. Explain how each factor works to increase or decrease enzyme activity, and identify whether that factor is used internally by the cell (i.e. for regulation of a chemical reaction) or acts externally (i.e. is a component of the environment or a human-influenced component). 58) Compare and contrast aerobic cellular respiration, anaerobic cellular respiration, and fermentation in terms of purpose, pathways used, the final electron acceptor, amount of ATP produced, method of phosphorylation to produce ATP, the use of an electron transport chain, the role of oxygen, and the end-products (other than ATP) which are produced.

59) Radioactive isotopes of various elements can be used to label molecules for use in studies of metabolic pathways. For example, 14C is a radioactive isotope of carbon and naturally occurs at much lower rates than non-radioactive 12C (i.e. most molecules contain 12C carbon atoms). A cell can be fed a nutrient molecule labeled with the radioactive isotope and scientists can detect where the radioactive isotope ends up. For each of the following scenarios, trace the radioactive isotope to where it ultimately would end up after moving through the cellular respiration, fermentation, or biosynthetic pathways. Only consider these metabolic pathways; do not consider any other cellular processes. A. E. coli is fed 14C-labeled glucose and grown under aerobic conditions. B. E. coli is fed 14C-labeled glucose and grown under anaerobic conditions (fermentation). C. E. coli is fed 14C-labeled fatty acids and grown under aerobic conditions. D. E. coli is fed 14C-labeled acetyl CoA and grown under conditions that promote biosynthetic pathways. 60) Describe how organisms can be classified in terms of their nutritional pattern. Specifically categorize organisms in terms of how they obtain organic carbon, the source of electrons for their redox reactions, and the source of energy to make ATP. Finally, use correct terminology to combine these categories to organize the types of organisms by their metabolic strategies.

Answer Key Testname: UNTITLED22

1) A 2) A 3) D 4) B 5) D 6) C 7) B 8) E 9) C 10) E 11) C 12) D 13) E 14) D 15) E 16) C 17) D 18) A 19) A 20) A 21) D 22) A 23) E 24) E 25) A 26) A 27) D 28) E 29) A 30) B 31) C 32) B 33) D 34) C 35) D 36) B 37) E 38) A 39) C 40) D 41) A 42) C 43) C 44) D 45) B 46) TRUE 47) FALSE 48) TRUE 49) TRUE 50) FALSE 17

Answer Key Testname: UNTITLED22

51) TRUE 52) TRUE 53) FALSE 54) TRUE 55) FALSE 56) All the chemical reactions that take place in a cell, including those reactions which release energy and those reactions which require energy, are collectively termed metabolism. Most metabolic reactions in a cell are organized into sets of reactions called biochemical pathways. Catabolic pathways break down substances and release energy. Anabolic pathways build new molecules from existing molecules, using energy in the process. The energy released from catabolic pathways is temporarily stored in a molecule called ATP. ATP has three phosphate groups. The terminal phosphate can be removed from the ATP to form ADP and release energy. This released energy can be used for anabolic reactions. ADP must continually be recharged, so a constant input of energy into the cell is required. The cycling of ADP to ATP, driven by energy from catabolic reactions and then back to ADP as the energy is released to fuel anabolic reactions, is a continual process in every cell. 57) The following factors may influence enzyme activity. 1) Cofactors/coenzymes are non-protein chemicals associated with certain enzymes and are necessary for enzyme function. They are cellular components and function internally. 2) Temperature is an environmental factor working externally to the cell. Increasing temperature up to the optimum will increase enzyme activity, but temperatures hotter than optimum will lead to a rapid decline in enzyme function as the enzyme denatures, or loses its shape. 3) An environmental pH value more acidic or more basic than the optimum pH of the enzyme will lead to a decline in enzyme activity due to changes to the enzyme's shape. 4) Enzyme activity will increase with increasing enzyme concentration relative to the substrate concentration. As substrate concentration increases, a saturation point will be reached where all enzymes are occupied by a substrate. Cells can regulate the amount of enzyme up or down to accommodate its need for a given product. 5) Cells can reversibly activate or deactivate enzymes based on need by adding or removing phosphate groups to the enzyme. 6) Competitive inhibitors are molecules that directly compete with the substrate to bind at the enzyme active site, thereby decreasing enzyme activities. Noncompetitive inhibitors interact with an enzyme at some location other than the active site, but decrease enzyme activity. Many pharmaceuticals, poisons, and toxins act as either competitive or non-competitive inhibitors. 7) Allosteric regulators bind with enzymes at a specific location called the allosteric site and may either activate or inhibit enzyme activity. This is often used by cells as an internal means of regulation. 58) Aerobic cellular respiration, anaerobic cellular respiration, and fermentation are all metabolic processes which organisms use to extract energy from nutrients and generate ATP. Aerobic cellular respiration and anaerobic cellular respiration use glycolysis, an intermediate step, the Krebs cycle, and an electron transport chain (respiratory chain). During both aerobic and anaerobic cellular respiration, substrate-level and oxidative phosphorylation are used to generate ATP. In aerobic cellular respiration, oxygen is the final electron acceptor, a maximum of 38 ATP per glucose molecule can be generated, and carbon dioxide and water are the end-products. In anaerobic respiration, the final electron acceptor is an inorganic molecule other than oxygen, and a reduced end-product is made by adding electrons and protons to the final acceptor. Carbon dioxide is also an end-product. The amount of ATP produced varies from more than 2 to less than 38 depending upon the specific respiratory chain used. During fermentation, oxygen is not required and fermentation occurs when the organism does not have a respiratory chain or when an appropriate final electron acceptor is not available. Only the glycolysis pathway is operational, and the final electron acceptor is an organic molecule, such as pyruvic acid or a derivative. Typical end-products of fermentation may include organic acids, alcohols, and gases such as carbon dioxide and hydrogen. Two ATP molecules are generated during the glycolysis pathway and fermentation does not add to that total.

Answer Key Testname: UNTITLED22

59) In scenario A, the 14C glucose would enter the glycolysis pathway where it would be split into 2 molecules of pyruvic acid. These would then move through the intermediate step and the Krebs cycle. During these pathways, carbon molecules are released as carbon dioxide; eventually all the carbons in glucose are released as CO2 so the radioactive isotope would ultimately be found in CO2. In scenario 2, the 14C-labeled glucose will enter glycolysis to become 2 molecules of pyruvic acid. The lack of oxygen will cause E. coli to use fermentation. Pyruvic acid will be reduced by electrons from NADH. Depending on which fermentation pathway is used, the 14C-label will eventually be found in the waste products of fermentation: various organic acids, alcohols, or CO2. In Scenario 3, fatty acids are broken down by beta-oxidation to form acetyl CoA which will enter the Krebs cycle. Carbons from acetyl-CoA will be released as CO2, so the radioactive carbon isotope will be found in CO2. In scenario 4, acetylCoA can be diverted from entering the Krebs cycle and instead be used to make fatty acids. In this case, the radioactive carbon isotope will be found in fatty acids and lipids. AcetylCoA can also enter the Krebs cycle then various intermediates can be diverted to make amino acids, so some radioactive carbon may end up in amino acids and proteins. 60) Organisms can either "fix" inorganic carbon dioxide into organic forms by adding hydrogen (autotrophs) or must have external source of organic carbon (heterotrophs). The initial source of electrons to power redox reactions can also be eith inorganic (lithotrophs) or organic (organotrophs), Energy can be obtained from light (phototrophs) or from the chemica of nutrients (chemotrophs). Photoorganoautotroph: light / organic electron source / fixes carbon Photoorganoheterotroph: light / organic electron source / cannot fix carbon Photolithoautotroph: light / inorganic electron source / fixes carbon Photolithoheterotroph: light / inorganic electron source / cannot fix carbon Photoorganoautotroph: light/ organic electron source / fixes carbon Chemoorganonheterotroph: nutrient breakdown / organic electron source / cannot fix carbon Chemolithoautotroph: nutrient breakdown / inorganic electron source / fixes carbon Chemolithoheterotroph: nutrient breakdown / inorganic electron source / cannot fix carbon

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) What is the definition of a true pathogen? A) must cause diarrhea, vomiting, and fever in the patient B) can only be a bacteria or a virus C) does not require a weakened host to cause disease D) needs to passed from one person to the next E) causes disease within one week of infecting the patient

2) Endemic infections A) are infections that are believed to be cured and wiped out by the year 2050. B) are infections that have only been recorded within the past 1,000 years and not before. C) are infections that are life threatening if not treated in a timely manner. D) are isolated infections in a particular population. E) are routinely detected in a population or region.

3) What is a pandemic? A) isolated infections in a particular population B) an infection where the host does not have signs or symptoms C) a widespread disease outbreak in a particular region during a specific time frame D) an infection routinely detected in a population or region E) a widespread disease outbreak that spreads to numerous countries during a specific time frame

4) How is a reemerging pathogen different from an emerging pathogen? A) A reemerging pathogen is an infectious agent that was identified previously in one location but is now emerging in a new separate location. B) A reemerging pathogen is an infectious helminth that was detected in one location of the body but receded and emerged from a second location. C) A reemerging pathogen is an infectious agent that was under control due to prevention or treatment strategies and is now resurfacing. D) A reemerging pathogen is an infectious agent that went away when the patient was taking antibiotics but quickly returned when the patient stopped taking the antibiotics. E) A reemerging pathogen is an infectious bacterial infection that manifests once every few months but goes away without treatment and only blisters the skin in another few months.

5) Why are Koch's postulates important to microbiology? A) They provide a way to select the most effective concentration of antibiotic to use for a patient. B) They allowed us to identify the causative pathogens of many infectious diseases. C) They explain how a particular disease produces specified signs in a patient. D) They demonstrate the preferred route of infection for a particular disease. E) They enable us to characterize the species of the infectious disease whether it is a bacteria, virus, or fungi.

6) Which of the following pathogen agents is multicellular? A) protozoans B) helminths C) bacteria D) viruses E) prions

7) Which of the following is an endogenous source of infection? A) contaminated food B) contaminated medical equipment C) contact with another person D) bacteria from the skin entering a surgical incision E) zoonotic disease

8) Which of the following is an indirect infectious disease transmission mode? A) vehicle B) vertical C) environment D) person to person E) animal

9) Which of the following infectious disease transmission modes is not correctly paired with an example? A) breast milk: HIV B) touching: cat-scratch fever C) windborne: cholera D) swimming: swimmer's ear E) flea bite: Plague

10) It is called a A) fomite B) zoonotic C) mechanical D) vehicle E) biological

vector when the vector organism has a role in the pathogen's life cycle.

10)

11) What is the order of the five stages of infectious disease? A) incubation period, acute phase, prodromal phase, convalescent phase, period of decline B) prodromal phase, acute phase, incubation period, period of decline, convalescent phase C) acute phase, prodromal phase, incubation period, convalescent phase, period of decline D) acute phase, incubation period, prodromal phase, convalescent phase, period of decline E) incubation period, prodromal phase, acute phase, period of decline, convalescent phase

11)

12) If you had to choose to be either a chronic carrier or an asymptomatic carrier, which would you choose any why? A) asymptomatic carrier because after the initial symptomatic infection I would only experience symptoms from time to time B) asymptomatic carrier because I wouldn't spread the infection C) chronic carrier because I would only spread the infection when having symptoms D) chronic carrier because I would be infected but never show signs or symptoms E) asymptomatic carrier because I wouldn't experience any symptoms

12)

13) Of the following goals listed, which are the two goals of epidemiology? I. isolate the infectious pathogen for study and vaccine creation II. describe the nature, cause, and extent of new or existing diseases in populations III. identify patient zero and how the initial infection occurred IV. intervene to protect and improve health in populations V. distribute vaccines so that future outbreaks do not occur A) I and III B) III and V C) II and IV D) I and II

13)

E) III and IV

14) When is knowing the host and environmental factors that lead to a disease more important to saving lives than knowing the etiological causative agent? A) when the host range is very large B) when the source of infection is a particular geographical location C) when the disease is spread through sexual contact D) when there is no cure for the disease E) when specific health factors within a person's control are particularly risky

14)

15) What are the three factors of the epidemiological triangle? A) time from exposure to symptoms, access to transportation, quality of hospitals B) pathogen type, host health, and geographic overlap C) survivability, length of acute phase, cultural factors D) environmental factors, etiological agent, and host factors E) vaccine use, disinfectant use, and hand-washing policy

15)

16) Which of the following is not a goal of the public health system? A) designs treatments, cures, or vaccines B) investigates C) prevents D) works to reduce health problems in the community E) diagnoses

16)

17) When is quarantine an effective tool to limit disease? A) when the disease has a long incubation time B) when the population is too spread out for vector control to be cost effective C) when the disease has a short incubation time D) when the population it too dense or poor for vector control to work E) when there is not enough funding for public education campaigns

17)

18) Why are epidemiological measures useful? A) They specify how much protection you need if coming into contact with someone that has the disease. B) They allow physicians to estimate when a patient can return to work. C) They help to track down patient zero. D) They allow the CDC to profile those most likely to need quarantine. E) They provide insight as to where public health campaigns or prevention efforts may be needed most.

18)

19) Which of the following would not be important when evaluating measures of frequency? A) incidence rate B) how the population is defined C) how long the infection lasts D) prevalence rate E) factors that may be linked to cases of the disease

19)

20) Which of the following would not be important when evaluating measures of association? A) number of sexual partners B) duration of the disease C) age D) geographical area E) ethnicity

20)

21) If a population contains 800 individuals and documents 400 cases of measles within the population, what is the prevalence rate? A) 30% B) 50% C) 60% D) 40% E) 80%

21)

22) What is the definition of morbidity? A) death B) existence of disease C) the number of infections during a specific time period D) deaths due to sexually transmitted infections during a specific time period E) the number of deaths during a specific time period

22)

23) Which of the following is an example of a rate? A) About 4,932 people become infected with HIV each day. B) 6 out of 10 deaths due to stroke are in women. C) 80 percent of women with gonorrhea do not have symptoms. D) In the United States, in people age 65 and older, there are 0.77 male/female. E) 1 in 4 people currently has a sexually transmitted disease.

23)

24) Which of the following is an example of analytical epidemiology? A) descriptive studies B) cross-sectional studies C) case reports D) observational studies E) correlation studies

24)

25) Which of the following is not a reason why healthcare epidemiology is essential to quality care? A) Healthcare-acquired infections add an extra $35 billion dollars per year to U.S. healthcare costs. B) Hospitals have been inadvertent sources of infection for thousands of years. C) Healthcare staff are dedicated to helping patients heal. D) About 75,000 people die from healthcare-acquired infections every year. E) Healthcare-acquired infection incidence increased by almost 40 percent from 1975 to 1995.

25)

26) Which of the following does not help to limit the spread of healthcare-acquired infections? A) consistent use of personal protective wear (gloves, masks, and gowns) B) dedicating equipment for a single patient's use whenever possible (a blood pressure cuff) C) environmental sanitization and equipment sterilization D) transporting patients as often as possible to keep the healthy patients away from the sick patients E) proper hand washing even if gloves will be worn

26)

27) Which of the following key HAI's is not associated with its correct cause? A) Pseudomonas aeruginosa: Causes infections in burn patients, catheterized patients, and people on ventilators B) Vancomycin-resistant enterococci (VRE): Causes wound, bloodstream, and urinary tract infections C) Methicillin-resistant Staphylococcus aureus (MRSA): Causes dangerous infections of surgical wounds, bedsores, and central lines; primarily transmitted by touch D) E. coli: Urinary tract infections and bacteremia E) Clostridium difficile: Causes acute illness that is followed by a high risk of chronic infection that causes severe liver damage and increases the risk of liver cancer

27)

28) Which of the following is not a reason why healthcare settings are hot zones for antibiotic-resistant pathogens? A) Caregivers may be overly fatigued and not wash their hands properly. B) There is extensive antibiotic use. C) Air is recirculated from patient isolation rooms to the rest of the hospital. D) There is an abundance of susceptible hosts. E) Healthcare staff caring for a high number of patients may wrongly assume that glove use can replace hand hygiene.

28)

29) When a healthcare provider diagnoses a reportable disease, who do they document the case with? A) FDA national database B) World Health Organization C) CDC national database D) local public health authority E) White House Epidemiology Center

29)

30) What are emerging diseases? A) diseases that were present hundreds of years ago but due to increased contact with fossils are now becoming active again B) infections that were central to one location but are now beginning to spread for unknown reasons C) new or newly identified infections in a population D) were previously found only in other mammals but are now starting to infect humans E) were previously under control, but are now showing increased incidence

30)

31) Which of the following is not a reason(s) that we see an increased rate of disease emergence? A) population crowding B) decreased water quality C) changes in sociocultural practices (such as injectable illicit drugs, widespread global travel, and increased food processing and handling) D) climate change E) deforestation and urbanization

31)

32) Which of the following factors would make eradication of a disease harder? A) only humans transmit and catch B) longer incubation period C) does not cause latent infections D) treatable or preventable E) easily identifiable

32)

33) What is the definition of eradication of an infectious disease? A) The patient no longer shows any symptoms. B) There are no longer any cases of the microbe anywhere in the world for three consecutive years. C) The patient has a zero blood count for the infectious microbe. D) There are no longer any cases of the microbe in the country. E) Ten or more developed countries have gone ten years without reporting one case.

33)

34) Which of the following is not a way that ethical issues emerge in epidemiology? A) new laws are passed B) more visible infections noticeable in the community C) more aware of old threats or diseases D) new threats or diseases E) new technologies or studies that provide more information or better insight

34)

35) What is herd immunity? A) small communities protect their children from being exposed to outside pathogens by limiting the contact their children have with outside visitors or workers B) the only protection available to those who choose not to receive immunizations due to religious belief C) at least 25 percent of the population needs to be immune before those too poor to receive the vaccination can be protected D) the protection offered to you by the size of your country, as it limits potential outside contact with an infected individual E) the only protection available to those who are unable to receive immunizations due to medical reasons

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) Chronic diseases have a rapid onset and progression.

36)

37) Zoonotic diseases are spread from animals to humans.

37)

38) The source of an infectious agent is the animate or inanimate habitat where the pathogen is naturally found.

38)

39) The acute phase of an infectious disease, when the pathogen levels are the highest, is the most contagious stage of any pathogen.

39)

40) The epidemiological triangle is equally useful for describing noninfectious diseases as it is infectious diseases.

40)

41) It is legal for the CDC to quarantine any person entering or already in the United States who may have an infectious disease that is deemed quarantinable.

41)

42) It can be challenging to accurately determine incidence rate for diseases with high percentages of asymptomatic cases or when a pathogen mutates to become more infective and/or virulent.

42)

43) When two things happen at the same time, that correlation indicates one factor is causing the other.

43)

44) Hospital microbiologists routinely test isolated pathogens for their susceptibility to commonly prescribed drugs in order to share these susceptibility rates with the healthcare team to help them make informed decisions about antibiotic therapies.

44)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 45) Name the five limitations of Koch's postulates. 46) Explain how and why healthcare epidemiology programs are essential to quality care. 47) What is the difference between reportable diseases and notifiable diseases?

Answer Key Testname: UNTITLED23

1) C 2) E 3) E 4) C 5) B 6) B 7) D 8) A 9) C 10) E 11) E 12) E 13) C 14) D 15) D 16) A 17) C 18) E 19) E 20) B 21) B 22) B 23) A 24) D 25) B 26) D 27) E 28) C 29) D 30) C 31) B 32) B 33) B 34) B 35) E 36) FALSE 37) TRUE 38) FALSE 39) FALSE 40) TRUE 41) TRUE 42) TRUE 43) FALSE 44) TRUE 45) They do not apply to noninfectious diseases, since those illnesses are not directly caused by pathogens. Other infectious agents called obligate intracellular pathogens, which include viruses and certain bacteria and protozoans, only replicate inside a host cell and are therefore impossible to grow as independent pure cultures. In still other cases, growing a microbe as a pure culture may cause it to attenuate, or lose its ability to cause disease. Furthermore, there are many human-specific infectious agents. Lastly, Koch's postulates do not easily deal with characterization of asymptomatic or latent disease. 8

Answer Key Testname: UNTITLED23

46) Healthcare epidemiology programs reduce transmission of infectious diseases through surveillance, prevention, and control programs. Since about 70 percent of HAIs are preventable; healthcare epidemiology programs have a significant opportunity to save lives. Estimates also show that every dollar invested in preventing nosocomial infections will lead to $3 of net direct cost savings. Furthermore, healthcare staff are there to increase the quality of life for their patients. 47) The diseases on a state or local tracking list are called reportable diseases. Usually the list of reportable diseases includes the diseases that the CDC has an interest in monitoring, as well as diseases that the local authorities want to monitor. The diseases that the CDC recommends monitoring are called notifiable diseases.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Host-microbe interactions A) involve a dynamic give-and-take between the microbe and the host. B) are always harmful. C) do not involve host factors. D) are generally commensal. E) never result in the normal species of the microbiota causing disease.

2) Examples of healthy host-microbe interactions with our normal microbiota include all except A) competition with pathogens. B) immune system maturation. C) moderation of immune attack against microbiota species while in their normal tissues. D) microbiota disruption. E) vitamin manufacture.

3) Which factors may result in a normal microbiota species causing disease? A) dysbiosis due to antibiotic therapy or invasion of other tissues by the microbiota species B) immune system attack on the host's own tissues C) invasion of other tissues by the microbiota species D) dysbiosis due to antibiotic therapy or immune system attack on the host's own tissue E) dysbiosis due to antibiotic therapy

4) Which statement shows an example of a commensal species in one host becoming a pathogenic species in another host? A) E. coli lives harmlessly in the appendix but will be attacked by the immune system if it invades the abdominal cavity. B) New infectious diseases are due to increases in host tropism. C) Up to 30% of pregnant women harbor Group B streptococci in the vagina to no ill effect, but when transmitted to their newborns, a proportion of babies develop serious infection. D) C. difficile flourishes in the large intestine after antibiotic therapy. E) Shigella flexneri preferably infects the tissues of humans and other primates.

5) The preference of a pathogen for a specific host is A) pathogenicity. B) dysbiosis. C) virulence. D) tropism. E) opportunism.

6) Which factor is responsible for many emerging pathogens in humans? A) expanded host or tissue range of the pathogen B) longer life spans resulting in a larger elderly population C) improved sanitation and hygiene practices D) availability of vaccines E) increased use of antibiotics in the past half-century

7) The degree or extent of disease that a pathogen causes is A) a host factor. B) attenuation. C) pathogenicity. D) virulence. E) toxicity.

8) Which is not a category of virulence factors? A) toxins B) adhesion C) immune system evasion D) nutrient acquisition E) attenuation

9) Properties that contribute to virulence A) are determined solely by the microbe. B) are determined by both the microbe and the host, and are fixed and unchanging. C) are determined solely by the host. D) are fixed and unchanging. E) are determined by both the microbe and the host, and may evolve over time.

10) What is an example of a virulence factor that is related to immune system evasion? A) LPS in Gram-negative cell wall B) fimbriae C) iron-binding protein D) flagella E) capsule

10)

11) Which is not an example of virulence as an evolving property? A) The 1918 influenza pandemic primarily killed young adults rather than elderly persons which is more typical of influenza both before and after that time. B) Historically, smallpox appeared to shift from a highly virulent pathogen which killed its victims quickly to one that did not kill immediately but more easily spread from person to person. C) Cold viruses which generate more coughs and sneezes while allowing the host to remain mobile will have an evolutionary advantage over those that cause their host to be bedridden. D) As hosts evolve more effective defenses against a given pathogen, the pathogen in turn will evolve virulence factors to combat those defenses. E) Each of these is an example of virulence as an evolving property.

11)

12) An attenuated pathogen A) has lost virulence factors needed to cause disease in an immune competent host. B) produces toxins. C) has become antibiotic-resistant. D) has recently acquired virulence factors allowing it to jump species. E) is part of the normal human microbiome.

12)

13)

13) ID50 describes A) the number of cells or virions needed to establish an infection in 50 percent of exposed hosts. B) the percentage of individuals which will develop an infection after exposure to 50 cells or virions. C) the number of cells or virions which will kill 50 individuals. D) the number of cells or virions which will kill 50% of exposed hosts. E) the amount of toxin lethal to a 50-pound human or other animal. 14) Which type of toxin is pictured?

14)

A) endotoxin B) type 1 exotoxin C) type 2 exotoxin D) type 3 exotoxin E) either type 1, type 2, or type 3 exotoxins 15) Which type of bacterial toxin is matched incorrectly with its description? A) endotoxin: enters the bloodstream during infection with Gram-negative bacteria B) toxemia: a toxin produced during a viral infection C) type 2 exotoxin: disrupt and damage the host cell membrane leading to cell lysis D) type 3 exotoxin: bind to a membrane receptor then enter the cell E) type 1 exotoxin: bind to the targeted host cell at a membrane receptor but do not enter the cell

15)

16) Exotoxins are A) secreted and only made by Gram-positive bacteria. B) secreted. C) secreted and the targets of some childhood vaccines. D) the targets of some childhood vaccines. E) only made by Gram-positive bacteria.

16)

17) Toxemia is a condition A) where a toxin has entered the bloodstream resulting in systemic effects. B) where a toxin is acting on tissues locally. C) that may describe both localized and systemic effects. D) where a vaccine is used to protect against a toxin. E) where a toxin acts as a superantigen.

17)

18) Septic shock is typically associated with A) either Gram-negative or Gram-positive infections. B) exotoxins or endotoxin. C) superantigens. D) exotoxins. E) Gram-negative infections.

18)

19) Which portal of entry is mismatched to its description? A) otic: pathogen enters via the ear B) ocular: via the conjunctiva C) gastrointestinal: often involves fecal-to-oral transmission D) parenteral: pathogen is passed from mother to child through the placenta E) urogenital: often associated with sexually-transmitted pathogens

19)

20) Which portal of exit will a bloodborne pathogen likely use? A) GI mucosa B) skin C) respiratory mucosa D) parenteral E) ocular

20)

21) Adhesins A) include molecules that bind to host factors such as fibronectin, sialic acid, and heparin / heparin sulfate. B) allow pathogens to stick to host tissues only in a nonspecific manner. C) include molecules that are typically found deep inside the pathogenic cell. D) are limited to only a few known types. E) make poor targets for vaccine development.

21)

22) Which type of invasin allows a pathogen to break down a blood clot that the body has generated to trap their spread? A) neuraminidase B) kinase C) flagella D) coagulase E) collagenase

22)

23) Pathogens can obtain iron from the body using A) siderophores. B) transferrin. C) proteases. D) siderophores or transferrin. E) lipases.

23)

24) Which method of hiding from the host immune system is incorrectly matched with its description? A) antigen masking: the pathogen covers itself in host factors to avoid detection of its own antigens B) antigen variation: the pathogen frequently switches its antigens C) antigen mimicry: the pathogen's antigens are similar in structure to host molecules D) latency: a pathogen exists quietly inside the host cell E) living intracellularly: a pathogen resides on the surface of a host cell where it is hidden by host cell surface molecules

24)

25) Which of the following is not a way that pathogens can avoid destruction by the phagocytes of the host immune system? A) adapt to living inside the phagocyte B) release toxins which kill the phagocyte C) make a capsule which is toxic to the phagocyte D) neutralize the hydrolytic enzymes produced by the phagocyte E) block fusion of the phagosome with the lysosome inside the phagocyte

25)

26) A potential antimicrobial drug is tested and found to strip away the capsules made by certain pathogenic bacteria. How would this drug affect the bacteria's ability to cause disease? A) The bacteria would be unable to survive inside the phagocyte. B) The bacteria would only be able to colonize surface tissues and not penetrate more deeply. C) The bacteria would not be able to kill phagocytes. D) The phagocytes would be better able to ingest the bacteria. E) The bacteria would be unable to acquire needed nutrients from the body.

26)

27) How are symptoms of an infection associated with the mode of transmission of the pathogen? A) Bodily fluids produced during an illness are often rich in infectious organisms. B) Lack of symptoms indicates that the infection is not transmissible to others. C) Bodily fluids are rarely a source of disease transmission during an infection. D) There is no relationship between symptoms and mode of transmission. E) The worse the patient feels, the more likely the disease is transmissible to others.

27)

28) Which of the following can be a potential disease reservoir for a pathogen which infects humans? A) only humans B) only humans or non-human animals C) environmental niches such as soil or water D) Humans, non-human animals, inanimate objects, or environmental niches can all serve as reservoirs for a pathogen which infects humans. E) only humans or inanimate objects that an infected human directly handles

28)

29) Criteria for assigning pathogens to a biosafety level include all the following except A) extent of disease and mortality rates. B) level of infectivity. C) availability of disease prevention and/or treatment. D) mode of transmission. E) ability to culture the pathogen using standard laboratory media and equipment.

29)

30) Which biosafety level is incorrectly matched with its description? A) BSL-1: non-pathogens or those that rarely cause disease in healthy people B) BSL-4: dangerous, lethal pathogens with no cures or treatments C) BSL- 2: known pathogens but the disease is treatable or preventable D) BSL-2+: known animal pathogens which do not infect humans E) BSL-3: serious, lethal pathogens though some diseases may be treatable

30)

31) Which of the following microbes are classified as BSL-2? A) Bacillus subtilis B) Both Staphylococcus aureus and Staphylococcus epidermidis C) Staphylococcus aureus D) Staphylococcus epidermidis E) E. coli K-12

31)

32) Which statement is true about standard precautions? A) They are used in student labs that only handle BSL-1 pathogens B) They are in force only for bloodborne pathogens. C) They require full face shields, gloves, and barrier gowns for all patient contact situations. D) They apply to all healthcare providers working with all patients. E) They are used only when the patient is known to be infected with a BSL-2 or higher pathogen.

32)

33) Which mode of transmission is not addressed by transmission precautions? A) airborne and droplet B) airborne C) vector D) droplet E) direct contact

33)

34) Droplet and airborne precautions A) both involve transmission through fine aerosols which require close contact for transmission. B) both require the use of a procedural mask. C) both involve diseases of the respiratory system and/or diseases transmitted through a respiratory route. D) both require isolation in a specially-ventilated room (AIIR). E) both require use of an N95 respirator.

34)

35) The role of healthcare workers in the management of disease outbreaks A) should be addressed through periodic training and re-training. B) is not critical in U.S. healthcare facilities. C) is only important in BSL-3 or higher facilities. D) is limited to properly using personal protective equipment. E) can be approached casually.

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) More than half of new infectious diseases in humans emerged due to expanded host tropism by the infectious organism.

36)

37) A microbe is either pathogenic or it is not. A microbe is either virulent or it is not. Both pathogenicity and virulence are all-or-nothing terms.

37)

38) A microbe with a low ID50 does not necessarily cause severe disease.

38)

39) A pathogen which uses a specific portal of entry will only be able to establish an infection in the system associated with that portal.

39)

40) A pathogen will always use the same portal for both entry and exit.

40)

41) While a reservoir can be a source of infection, not all sources of infection are reservoirs.

41)

42) Members of the genus Vibrio, which includes the species which cause cholera are found in marine environments. However, most cases of cholera occur when people drink water that has been contaminated with feces from other humans with cholera. If an effective vaccine against cholera were developed so that humans would become immune to the disease, both the reservoir and the source of the cholera bacteria would be eliminated.

42)

43) A newly emerged infectious disease whose pathogen cause has not yet been identified is lethal in more than 90% of cases. Epidemiological evidence suggests that this pathogen is transmitted only through direct contact with the blood of ill or recently deceased patients. Patient blood and tissue samples would best be handled at BSL-2 until more information can be learned about the pathogen.

43)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 44) Contrast pathogenicity and virulence, and describe why virulence can be considered an evolving property. 45) If you had the ability to genetically engineer a pathogenic bacterium, what features would you include? Choose a portal of entry and a portal of exit for your pathogen. Then choose three virulence factors from at least two the following areas: toxins, adhesins, invasins, acquisition of nutrients, and avoidance of the immune system, and describe how each factor will help your bacterium survive in the host. Your virulence factors should make sense for the portals of entry and exit that you chose. 46) You are a consultant with an architectural firm designing a BSL-3 hospital facility for patient care and diagnostic laboratory services. The facility will specialize in airborne pathogens such as Mycobacterium tuberculosis. Describe the characteristics of pathogens handled in a BSL-3 facility and describe at least five features that must go into the facility design.

Answer Key Testname: UNTITLED24

1) A 2) D 3) A 4) C 5) D 6) A 7) D 8) E 9) E 10) E 11) E 12) A 13) A 14) A 15) B 16) A 17) A 18) E 19) D 20) D 21) A 22) B 23) A 24) E 25) C 26) D 27) A 28) D 29) E 30) D 31) C 32) D 33) C 34) C 35) A 36) TRUE 37) FALSE 38) TRUE 39) FALSE 40) FALSE 41) TRUE 42) FALSE 43) FALSE 44) Pathogenicity is the ability of a pathogen to cause disease; virulence describes the degree or extent of disease that a pathogen causes. Whereas pathogenicity is an all-or-nothing term, virulence varies, may depend on both pathogen and host features, and may evolve over time. To endure over time, a pathogen's ability to break down defenses and live within a host must be balanced with the ability to transmit to others. A highly-virulent pathogen which is transmitted person-to-person and causes high-mortality outbreaks that rapidly kill or debilitate hosts usually remains geographically isolated and causes short-lived outbreaks. Over time, this pathogen may evolve into one which does not kill victims right away, thus increasing the time available for transmission. 8

Answer Key Testname: UNTITLED24

45) Answers to this question will be highly variable dependent upon student choice. The portals of entry and exit should be logically connected (for example, if the student chooses a gastrointestinal portal of entry such as the mouth, they should also choose a gastrointestinal portal of exit). When a selected virulence factor has a specific tissue or cellular target, this should also align to the portal of entry. 46) A BSL-3 facility handles pathogens which cause serious, sometimes lethal, human disease. Some pathogens in this category may be treatable. These pathogens may be contagious and transmitted through airborne routes, which means that the pathogen may remain infectious in the environment for some time. Besides all measures for BSL-1 and BSL-2 facilities, the BSL-3 facility should have: controlled access with self-closing double doors, airflow management such as airborne infection isolation rooms (AIIR) to keep airborne pathogens from other parts of the building, biological safety cabinets for pathogen handling and manipulation, decontamination facilities for waste and personal protective equipment that will be laundered, availability of gloves, protective lab coverings, and respirators for personnel which will remain in the BSL-3 facility, adequate warning signage detailing infection risks, and available vaccination and/or monitoring of personnel for infection.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following does not describe adaptive immunity? A) recognizes pathogens it previously fought, allowing for quicker and more aggressive defense mobilization upon later exposures to the same agent B) matures over time C) only in vertebrate animals D) generalized responses that don't vary based on the pathogen being fought E) evolved more recently

2) Which of the following features are shared between both innate and adaptive immunity? A) recognize diverse pathogens and eliminate identified invaders B) discriminate between self and foreign antigens C) respond immediately, remember antigens, and exist in all eukaryotic organisms D) respond immediately and remember antigens E) recognize diverse pathogens, eliminate identified invaders, and discriminate between self and foreign antigens

3) Which of the following is not a benefit of our normal microbiota? A) competes for nutrients with pathogens B) competes for space with pathogens C) generates an environment that limits pathogen survival D) makes substances that may directly damage pathogens E) neutralizes harmful wastes that pathogens produce

4) The general goal of first-line defenses is to A) destroy pathogens. B) isolate pathogens. C) weaken pathogens. D) prevent pathogen entry. E) tag intruders with a signaling molecule to identify them as foreign.

5) Which of the following is an example of a mechanical barrier? A) mucus B) antimicrobial peptides C) lysozyme D) stomach acid E) skin

6) Which of the following is an example of a chemical barrier? A) mucus B) tears C) urine D) skin E) antimicrobial peptides

7) Which of the following is not a reason the skin is a useful barrier? A) The skin is enriched with lipids to serve as a water-resistant layer. B) The skin is enriched with antimicrobial peptides. C) The skin is enriched with specialized proteins such as keratin. D) The outermost layer is made up of tightly compacted dead epithelial cells. E) The skin produces mucus to trap microbes.

8) Which of the following is false about the enzyme lysozyme? A) destroys viruses and fungi B) acts as a chemical barrier C) breaks down bacterial cell walls D) can be found in mucus, saliva, tears, and breast milk E) kills bacterial cells

9) Which of the following is true about antimicrobial peptides? A) Only destroy bacteria B) Produced by leukocytes C) Specifically target viral capsids for degradation D) About 50 different AMPs exist. E) It's rare for microbes to develop resistance to AMPs.

10) Antimicrobial peptides can do all of the following except A) regulate body temperature. B) target intracellular components. C) stimulate leukocytes. D) insert themselves into target cell membranes. E) disrupt plasma membrane and/or cell wall.

10)

11) What are the two categories of second-line defenses? A) red blood cells and antibodies B) assorted molecular factors and leukocytes C) mucus and lysozyme D) platelets and red blood cells E) antibodies and platelets

11)

12) In the correct order, what are the names of the fluid leaving the capillaries, going into the space between cells and then into the lymphatic capillaries? A) lymph, interstitial fluid, and plasma B) plasma, interstitial fluid, and lymph C) interstitial fluid, lymph, and plasma D) plasma, lymph, and interstitial fluid E) lymph, plasma, and interstitial fluid

12)

13) What is edema? A) irregular heart palpitations B) tissue swelling C) the spreading of a pathogen from the circulatory system to the lymphatic system D) the hardening of infected lymph nodes E) when a capillary bursts and is releasing fluid under the skin

13)

14) Which of the following are primary lymphoid tissues? A) spleen and mucosa-associated lymphoid tissue B) thymus and lymph nodes C) bone marrow and mucosa-associated lymphatic lymphoid tissue D) thymus and bone marrow E) lymph nodes and spleen

14)

15) From the image below, identify which of the following numbers are indicating primary lymphoid ti

15)

A) 3 and 4

B) 5 and 7

C) 1 and 8

D) 6 and 8

E) 1 and 2

16) Secondary lymphoid tissues A) filter lymph and sample surrounding body sites for antigens which are brought into contact with the leukocytes that reside in secondary lymphoid tissues to stimulate an immune response. B) are neutrophils and eosinophils. C) are where leukocytes mature. D) are where formed elements in blood are produced. E) are monocytes and dendritic cells.

16)

17) What role do erythrocytes play in our blood? A) form mesh like clots to trap pathogens B) give rise to white blood cells that phagocytize pathogens C) damage blood vessels when released by bacteria D) deliver oxygen E) clump together and help stem blood loss

17)

18) Which of the following is an agranulocyte? A) eosinophil cell B) basophil cell C) mast cell D) neutrophil cell E) dendritic cell

18)

19) What is the general classification used to categorize leukocytes? A) It depends on the age of the cell, as all agranulocytes start off as a granulocyte and later change their function and structure over the life of the cell. B) whether they function as part of the innate or adaptive immune system C) whether or not the cells contain a nucleus D) whether the cells originate from primary or secondary lymphoid tissues E) whether or not leukocytes have granules in their cytoplasm that are visible when stained and then viewed by light microscopy

19)

20) Which cell type is the most numerous white blood cell in circulation, is the first leukocyte recruited from the bloodstream to injured tissues, and releases potent antimicrobial peptides? A) basophils B) neutrophils C) dendritic cells D) monocytes E) eosinophils

20)

21) Which cell type has a nucleus that appears to have two lobes connected by a thin band, has granules that contain diverse enzymes and antimicrobial toxins, and has mediators that are expelled in response to certain allergens and parasites? A) neutrophils B) monocytes C) basophils D) eosinophils E) mast cells

21)

22) Which of the following images represents a mast cell that produces granules that act as the initial chemical alarm that recruits neutrophils and other leukocytes to the scene and simultaneously promotes early phases of inflammation? A)

22)

23) Which cell type works to prevent our immune system from attacking self and from over-reacting to nonthreatening substances, is abundant in tissues next to body openings, and phagocytizes a broad range of antigens? A) natural killer cells B) macrophages C) lymphocytes D) monocytes E) dendritic cells

23)

24) Which cell type is the largest agranular white blood cell, mature as they leave the circulatory system, and increase cell levels due to chronic infections and inflammation, autoimmune disorders, and certain cancers? A) mast cells B) lymphocytes C) natural killer cells D) monocytes E) dendritic cells

24)

25) Which cell type is a subgroup of lymphocytes, abundant in the liver, and has important roles in innate immune protection against viruses, bacteria, parasites, and even tumor cells? A) B cells B) dendritic cells C) macrophages D) T cells E) natural killer cells

25)

26) Which of the following is not a function of a molecular second line defense? A) recruiting leukocytes to the site of infection B) producing antibodies specific to the bacterial infection C) slowing the growth of the pathogen D) stimulating inflammation E) triggering fever

26)

27) Why are leukocytes so central to second-line molecular defenses? A) Leukocytes remove second-line molecular defenses to inhibit damage to healthy tissues in the surrounding area. B) Leukocytes trigger other cells of the immune system to produce second-line molecular defenses. C) Leukocytes have nothing to do with second-line molecular defenses. D) Leukocytes produce second-line molecular defenses. E) Leukocytes respond to the production of second-line molecular defenses.

27)

28) Which of the following pairs is not an example of a cytokine and its function? A) interferons: produced by virus-infected cells to signal neighboring cells to mount antiviral defenses B) chemokines: recruit white blood cells to areas of injury or infection C) eicosanoids: promote the replication and gathering of leukocytes D) interleukins: regulate inflammation, fever, T cell development, and innate and adaptive immune responses E) tumor necrosis factors: induce inflammation and kills tumor cells

28)

29) What are cytokines? A) organic chemicals which stimulate fever via an increase in metabolism B) signaling proteins that help cells communicate with each other, initiating and coordinating immune actions C) enzymes that promote the replication and gathering of leukocytes D) alert hormones that trigger the body to prepare for injury by shrinking capillaries and increasing platelet production E) carbohydrates which reduce inflammation in the body

29)

30) Which of the following is an example of a bacterial cell utilizing a siderophore to collect iron? A) Bacteria produce proteins that steal iron from host iron-binding proteins. B) Bacteria use manganese instead of iron. C) Hemolytic bacteria collect hemoglobin from host red blood cells and breaks them down to extract iron. D) Bacteria collect host iron-binding proteins and breaks them down to extract iron. E) Bacteria produce proteins that degrade host cells and cause the release of iron.

30)

31) Neisseria gonorrhoeae circumvents our iron-sequestering defenses by A) breaking down red blood cells to get to the iron-rich hemoglobin inside. B) capturing our iron-binding proteins and pulling the iron out of them for their own use. C) using manganese in their metal-requiring enzymes instead of iron. D) making siderophores that pull iron from our iron-binding proteins. E) releasing lytic enzymes and then scavenging the debris for iron.

31)

32) Where is the iron-binding protein transferrin found? A) neutrophil granules B) milk and tears C) saliva and mucus D) red blood cells E) blood plasma and extracellular fluids

32)

33) Which of the following describes the classical pathway of complement activation? A) Complement proteins activate when triggered by macrophages or neutrophils. B) Complement proteins activate when mannose-binding lectin binds to the pathogen. C) Complement proteins activate by coming into contact with certain blood-clotting proteins. D) Complement proteins activate when antibodies bind to a pathogen. E) Complement proteins activate by directly interacting with the pathogen.

33)

34) Which of the following is an outcome of complement activation? A) opsonization, cytolysis, and inflammation B) cytolysis and inflammation C) opsonization and cytolysis D) opsonization E) cytolysis

34)

35) Which of the following is not a way that bacteria can evade complement activation? A) release enzymes that break down antibodies that trigger complement activation B) build a capsule to hide surface antigens that would trigger complement activation C) release enzymes that break down lectins responsible for triggering complement activation D) release enzymes that break down complement proteins E) produce proteins that mimic our naturally occurring regulators of complement activation

35)

36) Which of the following is not a main goal of inflammation? A) deliver oxygen and nutrients B) recruit immune defenses to the injured tissue C) transport chemical factors essential for tissue recovery D) limit the spread of infectious agents E) produce localized heat and swelling in an effort to denature key bacterial proteins

36)

37) Which of the following are the three phases of inflammation? A) vasoactive release, diapedesis, and angiogenesis B) chemoattractant production, exudate release, and healing C) cytokine production, vasodilation, and phagocytosis D) margination, histamine release, and apoptosis E) vascular changes, leukocyte recruitment, and resolution

37)

38) Which of the following is not a cardinal sign of inflammation? A) loss of function B) swelling C) fever D) pain E) redness

38)

39) Which of the following key chemical mediators in inflammation is not matched to its function? A) histamine: induces vascular changes B) prostaglandins: induce vascular changes and stimulate pain receptors C) kinin: induces vascular changes, stimulate pain receptors, and assist in blood-clot cascades D) TNF-α: enhances inflammation E) thromboxanes: reduce pain receptor stimulation and reduces fever

39)

40) Chronic inflammation A) works to protect host tissues until all pathogens have been eradicated. B) is not useful or protective and promotes atherosclerosis, cancers, and neurodegenerative disorders. C) can lead to muscle aches and fatigue as the body struggles to heal itself. D) can take years to go away but will go away eventually. E) is only of concern if the chronic inflammation is occurring in or next to the brain.

40)

41) What triggers the release of cytokines, which signal the hypothalamus of the brain to raise the body's baseline temperature from 37°C to a higher temperature? A) interferon alpha B) pyrogens C) prostaglandins D) tumor necrosis factor E) interleukin 1

41)

42) Which of the following is not a potentially useful effect of a fever? A) enhances antiviral effects of interferons B) promotes tissue repair C) limits growth of certain pathogens D) increases phagocyte efficiency E) enhances cytokine production

42)

43) Which term describes an elevated body temperature that fluctuates, but doesn't reach normal in the course of the fluctuations? A) sustained fever B) remittent fever C) relapsing fever D) intermittent fever E) Pel-Ebstein fever

43)

44) Which term describes a fever lasting 3-10 days followed by a non-fever state of similar length? A) remittent fever B) sustained fever C) intermittent fever D) Pel-Ebstein fever E) relapsing fever

44)

45) Which of the following would you expect to see if your patient had been bitten by a tick infected with the Borrelia bacteria species? A) Pel-Ebstein fever B) quatan fever C) intermittent fever D) tertian fever E) relapsing fever

45)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 46) Skin is one of the most important physical barriers.

46)

47) Antimicrobial peptides are able to stimulate leukocytes and destroy bacteria by disrupting their plasma membranes.

47)

48) The spleen is a primary lymphoid tissue.

48)

49) Eosinophil granules contain diverse enzymes and antimicrobial toxins that are released into surrounding tissues in response to certain allergens and parasites.

49)

50) Dendritic cells prevent the immune system from attacking self and from over-reacting to nonthreatening substances.

50)

51) Molecular second-line defenses include cytokines, iron-binding proteins, and complement proteins.

51)

52) Ferritin is a specific example of a siderophore produced by Borrelia bugdorferi.

52)

53) Complement activation has three different outcomes but which outcome occurs depends on which complement pathway is activated.

53)

54) Kinins block histamine's actions and therefore serve as anti-inflammatory drugs.

54)

55) Pyretic drugs like aspirin, ibuprofen, and acetaminophen are all commonly used to reduce fever by increasing the production of prostaglandins in the hypothalamus.

55)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 56) Explain the hygiene hypothesis and describe one example that supports it. 57) Explain the mechanical and chemical barriers of the skin. 58) Explain the collection and flow of lymph. 59) Name two similarities between macrophages and dendritic cells. 60) Name three reasons why inflammation can be protective and useful?

Answer Key Testname: UNTITLED25

1) D 2) E 3) E 4) D 5) A 6) E 7) E 8) A 9) E 10) A 11) B 12) B 13) B 14) D 15) A 16) A 17) D 18) E 19) E 20) B 21) D 22) A 23) E 24) D 25) E 26) B 27) D 28) C 29) B 30) A 31) B 32) E 33) D 34) A 35) C 36) E 37) E 38) C 39) E 40) B 41) B 42) E 43) B 44) D 45) E 46) TRUE 47) TRUE 48) FALSE 49) TRUE 50) TRUE 11

Answer Key Testname: UNTITLED25

51) TRUE 52) FALSE 53) FALSE 54) FALSE 55) FALSE 56) The hygiene hypothesis proposes that decreasing the diversity and levels of microbes in our normal microbiota may negatively affect immune responses. (1) Studies performed on germ-free animals that were born and raised in microbe-free environments reveal that these animals have an underdeveloped immune system and struggle to combat pathogens. (2) People with chronic inflammatory disorders like irritable bowel disease (IBD) have clear shifts in the normal gut microbiota. In mouse models for IBD, Clostridia bacteria populations are especially decreased. (3) Pathogens face robust competition from the normal microbiota of the intestinal tract and may fail to find a niche to survive in unless the microbiota population is decreased. Clostridium difficile is a case in point of this. (4) Vaginal pH is kept low by lactic acid—producing bacteria called lactobacilli. A reduction in lactobacilli levels, as can occur following antibiotic therapies, leads to an increase in vaginal pH, which in turn allows the opportunistic pathogen Candida albicans (a yeast) to grow and cause a vaginal yeast infection. 57) Mechanical barriers rinse, flush, or trap pathogens to limit their spread into the body. Tightly compacted dead epithelial cells are constantly being sluffed off and as they do so, they carry away any bacteria that might be on them. Epithelial cells are enriched with specialized proteins (such as keratin) and lipids to serve as a water-resistant layer. The skin's relatively dry, low nutrient, salty, and slightly acidic environment inhibits the growth of many microbes. Certain fatty acids in sweat serve as additional chemical barriers. Certain skin cells also make antimicrobial peptides. 58) Interstitial fluid flows into lymphatic capillaries, where it is then called lymph. Lymph flows toward lymph nodes, is filtered and screened for invading agents, and finally rejoins the venous blood supply. Upon rejoining the blood it is no longer called lymph, but is now plasma. 59) Macrophages and dendritic cells use phagocytosis to clear invaders. They also activate the adaptive branch of immunity. 60) 1. Recruit immune defenses to the injured tissue. 2. Limit the spread of infectious agents. 3. Deliver oxygen, nutrients, and chemical factors essential for tissue recovery.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) How does adaptive immunity differ from innate immunity? A) Adaptive immunity's effects are immediate upon exposure to a pathogen. B) Adaptive immunity generates immunological memory and is specific to a pathogen. C) Adaptive immunity generates immunological memory and its effects are immediate upon exposure to a pathogen. D) Adaptive immunity generates immunological memory. E) Adaptive immunity is specific to each pathogen.

2) The branches of adaptive immunity are A) the cellular response and the humoral response. B) the humoral response and the memory response. C) the antigen response and the memory response. D) the cellular response and the memory response. E) the cellular response, the humoral response, and the memory response.

3) All the following apply to T cells except A) have the capacity to recognize virtually any type of antigen. B) originate in the bone marrow. C) mature in the thymus. D) reside in the lymphoid tissue. E) coordinate the humoral response by making antibodies.

4) All the following apply to B cells except A) originate in the bone marrow. B) play a critical role in both the cellular and humoral responses. C) mature in the bone marrow. D) reside in the lymphoid tissue. E) coordinate the humoral response by making antibodies.

5) Which T cell class is incorrectly matched with its description?

A) TC: attack other T cells during self-tolerance screening B) TH2: stimulate B cells to make antibodies C) TH1: stimulate TC cells D) Treg: ensures that immune responses subside once a threat subsides E) TH: identified by the CD4 proteins on the cell surface 6) The human immunodeficiency virus (HIV) selectively infects any cell which carries the CD4 surface glycoprotein. Which immune function will be impaired? A) stimulation of Tc cells and destruction of virally-infected cells B) stimulation of macrophage activity C) stimulation of B and Tc cells but not of macrophage D) stimulation of B cells and antibody production E) stimulation of macrophage, B and TC cells

A substance that may trigger an immune response, if presented in the right context is termed a(n) A) hapten. B) antigen. C) effector. D) antibody. E) cytokine.

8) While not a hard-and-fast rule, molecules may be ranked from more immunogenic to less immunogenic. Which shows the correct ranking form more immunogenic to less immunogenic? A) haptens > lipids > polysaccharides > proteins B) haptens > proteins > lipids > polysaccharides C) polysaccharides > lipids > proteins > haptens D) proteins > polysaccharides > lipids > haptens E) Only haptens are less immunogenic; lipids, polysaccharides, and proteins have about equal immunogenicity.

9) Which statement does not apply to haptens? A) Haptens are generally too small to be immunogenic on their own. B) Haptens are also known as incomplete antigens. C) Haptens are any nonpathogenic substance, rather than a microorganism, which can stimulate an immune response. D) Haptens must bind to a more complex molecule to stimulate an immune response. E) Antibiotics such as penicillin are often haptens.

10) What is the role of B cell receptors (BCRs) and T cell receptors (TCRs) in the immune response? A) to combine with haptens so they can stimulate an immune response B) to recognize specific epitopes of an antigen C) to communicate with lymphocytes and other white blood cells D) to release the cytokines needs for immune cell stimulation E) to release chemicals which destroy pathogens

10)

11) How is the immune system able to recognize a limitless number of different antigens and epitopes? A) Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope. B) Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope AND the immune system produces a wide variety of lymphocytes. C) While each lymphocyte carries receptors that recognize only one type of epitope, the immune system produces a wide variety of lymphocytes each of which carries unique receptors. D) If a lymphocyte encounters an antigen it does not recognize, it immediately switches receptors until it finds one that is a match. E) A genetic "memory" of the pathogens your parents encountered (and their parents and so on) is passed on to each generation, increasing the number of possible responses over time.

11)

12) Which statement provides the best explanation of the need for self-tolerance screening of lymphocytes? A) The process which generates the vast array of diverse antigen receptors is a highly-controlled process, so the generation of receptors which can bind to the body's own tissues is a rare occurrence due to a genetic mutation. B) Self-tolerance involves "self" lymphocytes which bind to and form a protective layer over all body tissues. C) Lymphocytes which would attack the body's own tissues are never generated. D) The process which generates the vast array of diverse antigen receptors is a random process that could produce receptors which will bind to the body's own tissues. E) It is necessary to have some lymphocytes with receptors that are self-tolerant to respond to intracellular infections by viruses.

12)

13) A newly-generated T cell can recognize MHCs and is not self-reactive. What is its fate? A) It will undergo genetic shuffling to change its receptor to increase self-tolerance. B) It will migrate to the bone marrow for screening for the ability to make antibodies against self-antigens. C) It will become part of an autoimmune attack in the body's tissues at some time in the future. D) It is signaled for destruction via apoptosis. E) It will migrate to the lymphoid tissues to await activation by its antigen.

13)

14) The cellular branch of adaptive immunity A) is based on the activity of both T and B cells. B) does not involve a memory function. C) is organized by T helper cells and carried out by T cytotoxic cells. D) is organized by T cytotoxic cells and carried out by T helper cells. E) is based on antibody production.

14)

15) What is the role of MHC I in the immune response? A) MHC I is found on all body cells except red blood cells. B) MHC I is found only on antigen-presenting cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells. C) MHC I is found on all body cells except red blood cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells. D) MHC I is found only on antigen-presenting cells. E) MHC I presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells.

15)

16) Which statement is not true about MHC II? A) MHC II interacts with the CD4 receptor on T helper cells. B) When bound to antigen, MHC II serves a key role in activation of the appropriate T cells. C) MHC II primarily displays extracellular antigens which have been phagocytized. D) MHC II is present only on antigen-presenting cells. E) MHC II interacts with both the CD4 and CD8 receptors on T helper and T cytotoxic cells.

16)

17) When "matching" a donated organ or tissue to a recipient, it is necessary that the donor and the recipient be as similar as possible. A) antibodies B) MHCs C) T helper cells D) APCs E) blood type

of the

17)

18) The two-signal activation process for T cells includes A) the presence of a superantigen AND binding between co-stimulatory proteins on the T cell and APC surfaces. B) the presence of a superantigen and the presence of appropriate antibodies. C) interaction of the T-cell receptor with the MHC-antigen complex on the APC AND the presence of a superantigen. D) the presence of antibodies AND binding between co-stimulatory proteins on the T cell and APC surfaces. E) interaction of the T-cell receptor with the MHC-antigen complex on the APC AND binding between co-stimulatory proteins on the T cell and APC surfaces.

18)

19) Which of the following is not required for T cell activation? A) bound antigen B) antibody C) involvement of CD4 or CD8 D) MHC I or II E) co-stimulatory proteins

19)

20) Which statement is not true about T cell subclass differentiation? A) Each subclass will include both effector and memory cells. B) T cell subclass differentiation is caused by the release of cytokines that is influenced by the antigen's nature and the amount present. C) Regardless of which T helper cell subclass develops during an immune response, the humoral response is not impacted. D) Which specific T helper cell subclass that develops may impact the progression and outcome of an infectious disease. E) Particular combinations of cytokines will favor the development of some T cell subclasses over others.

20)

21) Consider a genetic mutation which causes T helper cells to be unable to respond to stimulation by the cytokines which lead to TH2 differentiation. This mutation would cause a patient to be deficient

21)

in which activity? A) production of memory cells B) decrease of the immune response once the pathogen is eliminated C) action of macrophage D) action of cytotoxic T cells E) production of antibodies 22) The difference between T cell activation by normal antigens and T cell activation by superantigens is that superantigens A) are not processed and presented by APCs. B) cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen and suppress cytokine release. C) suppress cytokine release. D) are not processed and presented by APCs and cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen. E) cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen.

22)

23) Which lymphocyte type is shown attacking the infected cell in the figure?

23)

A) B cell B) helper T cell C) cytotoxic T cell D) antigen-presenting cell E) memory T cell 24) Cytotoxic T cells eliminate pathogens by A) ingesting and digesting infected or cancerous cells. B) ingesting and digesting cellular pathogens. C) releasing chemicals which cause infected or cancerous cells to undergo apoptosis. D) releasing chemicals which are toxic to cellular pathogens. E) coordinating the activities of other immune cells.

24)

25) What is the role of memory cells? A) suppress the cellular response once the infection has passed B) circulate in the body at elevated levels to maintain an active attack against any possible pathogen C) provide immune protection specifically for central nervous system D) remain in the lymphoid tissue to rapidly proliferate and differentiate upon subsequent exposure to the same pathogen E) prevent an immune response against members of the normal microbiota

25)

26) T-independent antigens A) are usually polysaccharides and able to bind multiple B cell receptors on a given B cell. B) are usually proteins. C) may be polysaccharides or proteins, and are not able to bind multiple B cell receptors on a given B cell. D) are able to bind multiple B cell receptors on a given B cell. E) are usually polysaccharides.

26)

27) Which is not a step in the process of B cell activation by a T-dependent antigen? A) binding of the antigen to the B cell receptor B) interaction between co-stimulatory proteins on the B and T cells C) processing and displaying the antigen with MHC II on the B cell D) release of cytokines by the T helper cell provide the second activation signal for the B cell E) binding of the antigen to a T helper cell receptor

27)

28) Which stage of the humoral response is pictured?

28)

A) B cell differentiation B) B cell activation by a T-independent antigen C) B cell proliferation D) isotype switching E) B cell activation by a T-dependent antigen

29) Which number on the diagram is labeling the portion of the antibody that makes it specific for the a is binds to?

A) 1

B) 2

C) 3

D) 4

29)

E) 5

30) Each antibody molecule consists of A) a "heavy" protein chain. B) various combinations of light and heavy protein chains. C) one light and one heavy protein chain. D) two light and two heavy protein chains. E) a "light" protein chain.

30)

31) Antibodies do all the following except A) neutralize antigens to prevent binding to host cells. B) increase phagocytosis by agglutination of antigens. C) activate killing by T cytotoxic cells. D) activate the complement cascade. E) increase phagocytosis by opsonization.

31)

32) Isotype switching occurs when A) an antibody changes which class it is. B) a B cell changes which antibody class it is producing. C) an antibody changes epitope it can recognize. D) activated B cells differentiate into either plasma or memory cells. E) a B cell switches which epitope it recognizes.

32)

33) Advantages of isotype switching include A) ability to respond to multiple epitopes of the same antigen with the same B cell. B) rapid response when a pathogen engages in antigen variation. C) ability to respond to multiple epitopes of the same antigen with the same B cell, expanded antibody response as different isotypes predominate in different areas of the body, and rapid response when a pathogen engages in antigen variation. D) expanded antibody response as different isotypes predominate in different areas of the body. E) ability to respond to multiple epitopes of the same antigen with the same B cell and rapid response when a pathogen engages in antigen variation.

33)

34) The most abundant antibody class in the body, found in all body fluids, is A) IgA. B) IgD. C) IgE. D) IgG.

34) E) IgM.

35) The antibody class which is involved in fighting parasites is A) IgA. B) IgD. C) IgE.

D) IgG.

E) IgM.

36) The antibody found in breastmilk and coating mucous membranes is A) IgA. B) IgD. C) IgE. D) IgG.

E) IgM.

37) Generally, the first antibody class made upon a primary antigen exposure is A) IgA. B) IgD. C) IgE. D) IgG.

E) IgM.

35)

36)

37)

38) IgE antibody, which is associated with allergic responses, A) is passed from mother to child through breastfeeding and may prevent the development of allergies in the child. B) encourages mast cells and basophils to release chemicals such as histamine and leukotrienes. C) is resistant to destruction by stomach acid. D) is usually found circulating in the bloodstream. E) can be found bound to B cells.

38)

39) A patient antibody titer which shows an increasing level of IgM but very little IgG would likely indicate that A) the patient is in the early stages of developing an immune response. B) the patient has nearly recovered from the infection. C) the patient is having an allergic reaction. D) the patient is currently a nursing mother. E) the patient was vaccinated against this pathogen rather than having the infection.

39)

40) In contrast to a primary immune response, immunological memory A) generates antibodies with enhanced affinity for its antigen. B) generates higher antibody titers. C) provides a rapid reactivation of humoral responses only by generating higher antibody titers and antibodies with increased affinity for its antigen. D) provides a rapid reactivation of both cellular and humoral responses including generating higher antibody titers and antibodies with increased affinity for its antigen. E) provides a rapid reactivation of both cellular and humoral responses.

40)

41) The amount of antibody present in the blood is termed the antibody A) effector B) specificity C) affinity D) titer

41)

. E) isotype

42) The graph shows

42)

A) primary antigen exposure. B) natural passive immunity. C) secondary antigen exposure. D) immunological memory. E) likely immune response upon exposure to a pathogen for which the patient has been vaccinated. 43) By which means of acquiring immunity is likely to produce the longest lasting protection? A) passive B) active C) natural D) artificial E) Active, artificial, natural, and passive all provide equally long-lasting protection.

43)

44) Postexposure prophylaxis, a form of artificial passive immunity, is often given when a person is bitten by an animal that is suspected of having rabies, or if the rabies-status of the animal cannot be confirmed. What specifically, is being given to the patient in this type of treatment? A) antigen-presenting cells which increase the rate at which the rabies antigens can be presented to T cells for activation B) antigens from the rabies virus C) effector B and T cells from a host who has developed an immune response to the rabies virus D) memory cells from a host who has developed an immune response to the rabies virus E) antibodies harvested from a host who has developed an immune response to the rabies virus

44)

45) Pregnant women are usually advised to be vaccinated against influenza to protect themselves and the baby after birth. The mother will acquire immunity from the vaccine while the baby will acquire immunity. A) artificial active; artificial active B) artificial active; natural passive C) artificial passive; artificial passive D) natural active; natural passive E) artificial active; artificial passive

45)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 46) Both the cellular and humoral branches of adaptive immunity have the goal of eliminating an identified antigen, but only the humoral branch develops a memory of the antigen so that future responses are faster.

46)

47) An antigen may consist of multiple epitopes, each of which recognized by different lymphocytes.

47)

48) Allorecognition occurs when B and T cells are screened for self-tolerance.

48)

49) Graft-versus-host disease occurs when transplanted bone marrow gives rise to B and T cells that attack the recipient's tissues.

49)

50) T cell subclass differentiation allows T cell clones to recognize different epitopes of the same antigen.

50)

51) Both the light and the heavy chains of an antibody are involved with epitope recognition and binding.

51)

52) The humoral immune response can enhance phagocytosis by either direct interaction of antibodies with their antigen, or though antibody activation of the complement cascade.

52)

53) Isotype switching of antibodies is beneficial because some pathogens are able to alter their antigens.

53)

54) A patient with a high antibody titer to a pathogen for which there is no vaccination indicates that this person is currently infected with the pathogen or was infected in the past.

54)

55) Artificial immunity is characterized by short-lived protection immune protection because the patient is not making their own memory cells or antibodies.

55)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 56) List and describe the four stages that occur during both the cellular and humoral response. 57) Adaptive immune responses are specific to a particular antigen. Provide and explain 3 examples which illustrate this concept. 58) Describe how antibodies are used to eliminate antigens. 59) Describe the basic structure of an antibody and detail the function of each of the 5 antibody classes. 60) Describe the two ways humoral immunity may be acquired, and describe the active and passive forms of each.

Answer Key Testname: UNTITLED26

1) B 2) A 3) E 4) B 5) A 6) E 7) B 8) D 9) C 10) B 11) C 12) D 13) E 14) C 15) C 16) E 17) B 18) E 19) B 20) C 21) E 22) D 23) C 24) C 25) D 26) A 27) E 28) B 29) D 30) D 31) C 32) B 33) D 34) D 35) C 36) A 37) E 38) B 39) A 40) D 41) D 42) A 43) B 44) E 45) B 46) FALSE 47) TRUE 48) FALSE 49) TRUE 50) FALSE 13

Answer Key Testname: UNTITLED26

51) TRUE 52) TRUE 53) FALSE 54) TRUE 55) FALSE 56) Stage 1 is antigen presentation. Antigen-presenting cells process and present antigens to T cells. B cells can directly interact with antigens without presentation by another cell. Stage 2 is lymphocyte activation. Successful antigen presentation causes the release of signaling molecules called cytokines which act on both T and B lymphocytes. Stage 3 involves lymphocyte proliferation and differentiation. Activated lymphocytes undergo many rounds of cell division to generate a collection of cloned cells. These cells may differentiate into effector cells or memory cells. Stage 4 is antigen elimination and memory. Effector cells will carry out activities to eliminate the antigen, while memory cells endure in lymphatic tissue long after the antigen has been eliminated. Memory cells provide a rapid recognition of the antigen if it is encountered in the future. 57) 1) Lymphocytes will recognize antigen using surface proteins called T cell receptors (TCRs) or B cell receptors (BCRs). Each lymphocyte is covered with many copies of these receptors, but each receptor on a given lymphocyte only recognizes one specific epitope of one specific antigen. 2) The body makes a diverse variety of TCRs and BCRs through a gene shuffling process as lymphocytes mature, so the body's capacity to respond to different antigens is nearly limitless. It is possible that during lymphocyte maturation, a cell with a receptor that responds to a molecule on normal body cells will be generated. To avoid an immune attack on normal cells, maturing lymphocytes are screened for self-tolerance. Those that attack normal cells are eliminated in this process. 3) Body cells are identified as "self" through a group of surface proteins called major histocompatibility complex (MHC) proteins. All body cells (except red blood cells) wear MHC 1 proteins, while immune cells which present antigen also wear MHC 2 proteins. When a cell is infected, altered such as by cancer, or has ingested an antigen for presentation, the foreign antigens will be displayed by the MHC proteins for recognition by T and/or B lymphocytes with receptors that recognize that antigen. To insure successful organ transplants, donor and recipient tissue must be matched so that their MHC proteins are as similar as possible. 4) During T cell activation, presentation of antigen by an antigen-presenting cells preferentially activates T cells whose receptors bind to that antigen. After activation, proliferation, and differentiation, all T cells clones will respond to the antigen that stimulated the original response. T cytotoxic cells will locate and eliminate cells displaying the specific antigen in question. 5) During a humoral response, a B cell with the correct receptor will bind to an antigen. After proliferation and differentiation of the B cell clones, the plasma B cells will secrete large quantities of antibody molecules who are able to specifically bind to the antigen which stimulated the B cell line. 58) Antibodies bind to the antigen that triggered the activation of the B cell line that produced them. Antibodies activate the complement cascade, which leads to cytolysis, inflammation, and opsonization. Antibodies can neutralize antigens by binding to them. By binding to the antigen, the antibodies prevent toxins, viruses, or bacteria from binding to their targeted host cell receptors. Finally, antibodies can directly increase the process of phagocytosis. Antibody-binding causes precipitation of small, soluble antigen which make them more detectable to phagocytes. When binding to larger antigens, antibodies cause agglutination of groups of cells which can then be more efficiently ingested by phagocytes. Antibodies also serve as tags, or opsonins, to mark antigens for phagocytosis. 59) Each antibody molecule is made up of four protein chains: two identical "light" chains and two identical "heavy" chains. The four chains are held together by covalent disulfide bonds. The antibody shape can be approximately thought of as a "Y". At the tip of each branch at the top of the "Y" is the site where the antibody binds to its antigen. The five antibody classes in order of abundance are IgG, IgM, IgA, IgE, and IgD. IgG is found in blood and all body fluids. It has strong neutralization, complement activation, and opsonization activity, and is the only antibody to cross the placenta to protect the fetus. IgA may occur as a monomer or dimer, and is abundant in mucous secretions and coating the mucous membranes. IgA has strong neutralizing capability, and is secreted in breastmilk; it is also resistant to stomach acid. IgM is the first antibody made during a primary immune response. It occurs as a monomer or pentamer. It has strong complement activation and agglutination/precipitation activity. IgE is relatively rare. Its key role is fighting parasite infections by encouraging mast cells and basophils to release histamine and other inflammatory mediators. This also explains its role in allergic responses. IgD is the least abundant antibody. It is primarily found bound to B cells and it specific function is poorly understood. 14

Answer Key Testname: UNTITLED26

60) Both active and passive forms of humoral immunity may be acquired through either natural or artificial means. Active immunity involves the patient generating their own immune response, specifically the production of memory cells and high antibody titers. Passive immunity involves the transfer of antibodies made by another host to an individual. Because the individual did not generate the response themselves, the immunity only lasts as long as the antibodies remain in circulation, usually only a few days to weeks. Natural active immunity occurs when a patient contracts an infection and generates an effective immune response to that infection. Artificial active immunity is generated through vaccination. Natural passive immunity is the transfer of antibodies from a mother to her unborn child as the mother's IgG antibodies cross the placenta, or to the baby after birth through breastfeeding. This protects the baby until its own immune systems is fully functional. Artificial passive immunity involves the medical transfer of antibodies generated by the exposure of another host (person or animal) to an antigen. Examples of this include antivenom treatment for snakebites, antitoxin treatment, or an effort to treat the victim of an otherwise incurable disease using antibodies from a survivor.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following can cause primary immunodeficiencies? A) aging B) medical interventions C) infectious agents D) systemic disorders E) congenital immunodeficiency

2) Which of the following is not a hallmark sign of primary immunodeficiencies? A) persistent B) recurring C) severe D) uncommon E) acute

3) What two types of patients help demonstrate that cancer can be considered a failure of the immune system? A) migraine patients and digestive issue patients B) transplant patients and HIV/AIDS patients C) nervous system complication patients and pulmonary system complication patients D) rheumatoid arthritis patients and multiple sclerosis patients E) hepatitis C infected patients and human papilloma viruses infected patients

4) Which of the following is not a proposed explanation for the development of autoimmunity? A) If a pathogen has antigens that resemble host factors, it could trigger the production of antibodies that cross-react with host tissues. B) Certain antigens in a person's diet could trigger the production of antibodies that cross-react with host tissues. C) Cytopathic effects generated by a pathogen could encourage host antigen-presenting cells to process and present self-antigens to T cells. D) Certain pathogens may release superantigens that inappropriately activate certain T cells against self-factors. E) Genetics

5) Autoimmune disorders are A) acute infections that target the immune system. B) caused by the immune system not being stimulated enough in adolescence and as a result is over reactive and can cross-react with host tissues. C) genetic conditions present from birth that continually degrade over time. D) chronic conditions that develop from the immune system attacking healthy self-tissues that should normally be left alone. E) short-term mistakes made by the immune system that are quickly recognized and self-limited.

6) Autoimmune disorders are diagnosed using A) detection of autoantibodies. B) family history. C) metabolic factors. D) a collection of tests and careful assessment of signs and symptoms. E) blood tests.

7) The erythrocyte sedimentation rate is used to monitor A) declining health in aging patients. B) anemia. C) inflammation. D) pregnancy. E) infectious status.

reactions are inappropriate responses against a threat that lead to immune-based pathologies such as allergy and autoimmunity. A) Aversion B) Endopathic C) Hypersensitivity D) Autopathic E) Sensitivity

9) Immune complex reactions belong to which class of hypersensitivity reactions? A) type I B) type II C) type III D) type IV

9) E) type V

10) Which of the following class of hypersensitivity reactions is not associated with autoimmunity? A) allergies B) cytotoxic C) autoimmune D) delayed hypersensitivity E) immune complex

10)

11) A patient that experiences a tuberculin skin test reaction is experiencing which class of hypersensitivity reactions? A) type I B) type II C) type III D) type IV E) type V

11)

12) Which of the following is not a type I hypersensitivity reaction? A) eczema B) seasonal allergies C) food allergy D) Goodpasture syndrome E) allergy-based asthma

12)

13) Which of the following factors impacts the signs, symptoms, and severity of an allergic response? A) IgE production B) family history C) family history, route of exposure, and IgE production D) route of exposure E) route of exposure and IgE production

13)

14) Which of the following describes how the hygiene hypothesis is related to type I hypersensitivity reactions? A) Food allergies have increased 3-fold in chronically poor families as compared to wealthy families in the United States. B) Children living on a farm are 25 percent more likely to experience seasonal allergies than children living in a large city. C) Up to 30 percent of people in undeveloped countries suffer from allergic rhinitis. D) Wealthy individuals are 10 times more likely to experience anaphylactic shock as compared to someone raised in an orphanage during adolescences. E) Between 1997 and 2011, the incidence of food allergies in the United States increased by 50 percent.

14)

15) Localized anaphylaxis tends to feature isolated symptoms such as A) decreased blood pressure, shortness of breath, or abdominal pain. B) confusion, hives, or hoarseness. C) watery eyes, a runny nose, or a confined rash. D) fainting, chest pain, or vomiting. E) anxiety, nausea, or swelling.

15)

16) What is the difference between an intolerance and an allergy? A) Intolerances can change over a patient's lifetime, but allergic reactions do not change throughout a patient's life. B) Intolerances occur due to a patient's exposure to the environment, while allergic reactions are genetically determined. C) Intolerances have mild symptoms, while allergic reactions can be life threatening. D) Intolerances tend to have a delayed onset of symptoms, while allergic reactions occur rapidly. E) Intolerances produce symptoms that last several days, while patients having an allergic reaction recover in less than 24 hours.

16)

17) Health care providers determine the specific allergen that is generating symptoms by using a blood test to look at levels. A) IgD B) IgG C) IgA D) IgM E) IgE

17)

18) Which of the following allergies and treatments is mismatched? A) anaphylaxis: epinephrine may be administered and emergency medical care must be sought B) allergic asthma: inhaled drugs that open up the bronchi C) atopic dermatitis: usually treated topically with ointments that may contain steroid anti-inflammatory drugs D) food allergy: managed on a contact basis using antihistamines like Benadryl E) insect bite/sting allergy: continued preemptive treatment with an injected antibody preparation that ties up the patient's IgE antibodies

18)

19) In desensitization immunotherapy, an antigen is used to stimulate cell 2, which can then stimulate cell 3 and cause the production of item 4. Identify cell 2, cell 3 and item 4. A) T helper 1 cell, T helper 2 cell, and IgG antibodies B) T regulatory cell, mast cell, and IgD antibodies C) T regulatory cell, T helper 2 cell, and IgE antibodies D) T regulatory cell, T helper 1 cell, and IgG antibodies E) mast cell, T helper 2 cell, and IgE antibodies

19)

20) Desensitization immunotherapies are least effective to treat allergies from which of the following? A) bee stings B) dust mites C) milk D) pollen E) fire ant stings

20)

21) Graves' disease is an example of which of the following type II hypersensitivity cytotoxic reactions? A) Antibodies interact with a cell-surface receptor on self-cells causing the inactivation of the receptor. B) Antibodies directly recruit leukocytes to lyse tagged extracellular cells C) IgM binds to nonsoluble antigens on the surface of a cell causing complement cascade activation to lyse cells. D) Antibodies interact with a cell-surface receptor on self-cells causing the overactivation of the receptor. E) IgG binds to nonsoluble antigens on the surface of a cell causing complement proteins to opsonize the target, thereby tagging it for phagocytosis.

21)

22) Which of the following examples of type II hypersensitivities are matched incorrectly with their mediated mechanism? A) rheumatic heart disease: cytolytic B) Goodpasture syndrome: noncytolytic C) Graves' disease: noncytolytic D) hemolytic disease of the newborn: cytolytic E) myasthenia gravis: noncytolytic

22)

23) A patient with the antigens A and RH+ would not be able to receive blood from which of the following? A) OB) B+ C) AD) A+ E) O+

23)

24) In which of the following cases is RhoGAM not given to the RH- mother in order to prevent hemolytic disease of the newborn? A) after amniocentesis or chorionic villus sampling B) around the 8th week of pregnancy C) following an episode of vaginal bleeding during pregnancy D) within 72 hours of delivery E) subsequent to miscarriage or abortion

24)

25) In what situation is hemolytic disease of the newborn a life and death situation? A) when an RH- women and an RH+ male have intercourse

25)

B) when an RH- mom is pregnant for the second time with an RH+ fetus C) when an RH- mom is pregnant for the first time with an RH+ fetus D) when an RH+ women and an RH- male have intercourse E) when an RH+ mom is pregnant for the second time with an RH- fetus

26) Which of the following statements about type III hypersensitivities is false? A) Relatively large antigen-antibody aggregates form. B) They develop when IgD or IgE antibodies bind to insoluble targets. C) Antibodies involved in type III reactions can be made as part of an autoimmune response or formed as a normal response to foreign antigens. D) Massive inflammation is triggered by the antibody aggregates activating complement cascades. E) Insoluble complexes are deposited in tissues.

26)

27) Which of the following diseases makes antibodies against centromeres and topoisomerases? A) poststreptococcal glomerulonephritis B) scleroderma C) systemic lupus erythematosus D) Sjögren's syndrome E) rheumatoid arthritis

27)

28) Although antivenom can save lives, it can also cause what type of reaction in certain patients? A) type I hypersensitivity B) nonautoimmune type III hypersensitivity C) type II hypersensitivity D) autoimmune type III hypersensitivity E) type IV hypersensitivity

28)

29) Which of the following would not cause serum sickness? A) sulfa drugs B) antivenom C) anti-inflammatory drugs D) antitoxin E) penicillin

29)

30) Which of the following are used to treat serum sickness? A) antihistamines B) anti-inflammatory drugs, antihistamines, and sulfa drugs C) sulfa drugs D) anti-inflammatory drugs E) anti-inflammatory drugs and antihistamines

30)

31) Which of the following hypersensitivities are T cell-mediated responses against self-antigens or otherwise harmless antigens? A) type IV hypersensitivities B) type I hypersensitivities and type II hypersensitivities C) type II hypersensitivities D) type I hypersensitivities E) type III hypersensitivities

31)

32) Why are type IV hypersensitivities called delayed hypersensitivity reactions? A) Type IV reactions affect nerve cells and cause nerve impulses to slow resulting in visibly slower movements from the patient. B) Drugs to counteract type IV reactions are large and slow to be absorbed by the affected cells causing the patient to tolerate a lengthy symptomatic phase before recovery is complete. C) Type IV reactions manifest slowly over 12-72 hours after the stimulating antigen is encountered. D) Although type IV reactions can cause skin lesions, watery eyes, and a runny nose, treatment for those symptoms needs to be delayed due to the rapid drop in blood pressure which soon follows and needs to be dealt with first. E) Type IV reactions only occur in underdeveloped countries and medical attention often needs to be delayed until the patient can be brought to a hospital.

32)

33) Which of the following is an autoimmune type IV hypersensitivity? A) multiple sclerosis B) Guillain-Barré syndrome, Hashimoto thyroiditis, multiple sclerosis, and celiac disease C) graft-versus-host disease D) celiac disease E) Hashimoto thyroiditis

33)

34) Allografts are A) transplanted tissue from an identical twin. B) interspecies transplants. C) similar to the host, but not genetically identical. D) transplants that are made in an immune-privileged site in the body are the least likely to be rejected. E) transplants from self, like a self-skin graft from one part of the body to another location.

34)

35) What is graft-versus-host disease? A) It occurs when tissue from an allograft is rejected. B) Immune system cells in transplanted bone marrow attack the body of its new host. C) Immune system cells of the host attack the newly transplanted bone marrow and reject it. D) It occurs when tissue from a xenograft is rejected. E) It occurs when tissue from an isograft is rejected.

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) Currently, there are no cures or preventions for autoimmune disorders.

36)

37) An allergen is any antigen that triggers IgE production and leads to a scenario where the immune system fights off a perceived threat that would otherwise be harmless.

37)

38) An allergy is a scenario where the immune system fights off a perceived threat that would otherwise eventually cause the breakdown of skin or other localized tissue.

38)

39) Any allergen can cause an anaphylactic response, but usually this dangerous scenario is caused by injected or ingested allergens such as foods, drugs, and insect venoms.

39)

40) If the patient has an allergy to the tested allergen, then the skin develops a lesion consisting of a flattened reddened area called the wheal and a raised, inflamed area called the flare.

40)

41) The blood type AB+ is referred to as the universal donor.

41)

42) The antibodies involved in type III reactions can be made as part of an autoimmune response or formed as a normal response to foreign antigens.

42)

43) A contributing factor to increasing latex sensitivities among healthcare workers is that wearing gloves on a regular basis often causes dry, cracked skin that may promote entry of the latex into the skin to trigger sensitization.

43)

44) Immune-privileged sites include the eye, brain, uterus, and testicles.

44)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 45) Why is it challenging for clinicians to narrow down the autoimmune disorder at play and how is it diagnosed in the end? 46) Why would someone allergic to pecans want to avoid other tree nuts as well? 47) Explain the difference between Celiac disease and an actual gluten allergy.

Answer Key Testname: UNTITLED27

1) E 2) E 3) B 4) B 5) D 6) D 7) C 8) C 9) B 10) A 11) D 12) D 13) C 14) E 15) C 16) D 17) E 18) E 19) D 20) C 21) D 22) B 23) B 24) B 25) B 26) B 27) B 28) B 29) C 30) E 31) A 32) C 33) C 34) C 35) B 36) TRUE 37) TRUE 38) FALSE 39) TRUE 40) FALSE 41) FALSE 42) TRUE 43) TRUE 44) TRUE

Answer Key Testname: UNTITLED27

45) It can be challenging for clinicians to narrow down the autoimmune disorder at play due to the large number of options, variability of symptoms, and the fact that signs and symptoms can take a long time to fully develop and may change over time. Diagnosis often involves detecting self-reactive immune system cells and/or autoantibodies, which are antibodies that bind to self-tissues. Depending on the suspected disorder, the clinician may also order other hematological tests (blood tests) that look for specific inflammation and metabolic factors. An autoimmune disorder is rarely definitively diagnosed using a single test; instead, a collection of tests and careful assessment of signs and symptoms are required. Some autoimmune disorders have scoring criteria to help clinicians make a diagnosis. As a generic example, if the patient met five out of a dozen criteria for a particular disorder, then he or she might have an 85 percent likelihood of being affected by it, based on historical data. Typically, the more criteria a patient meets in such a scoring system, the greater the chance that the diagnosis is accurate. 46) Allergens may share antigenic features. This means that a sensitizing exposure to one allergen may generate a cross-reactivity to other related allergens. For example, a person may only ever have been exposed to pecans, but the generated IgE antibodies may cross-react with antigens in walnuts, almonds, and cashews, rendering the patient allergic to all of those foods even if they have never been directly exposed to them. For this reason, a person who reacted against one tree nut would be advised to avoid all tree nuts as a precaution. 47) Celiac disease is sometimes called gluten allergy, but actually isn't, since IgE does not mediate it. Exposure to gluten–a protein found in wheat, rye, and barley–causes T cells to attack the lining of the small intestine within 2-3 days of consuming it. Extreme inflammation and tissue damage result, interfering with the ability to absorb essential vitamins and minerals from food.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) In the practice of variolation, how were patients exposed to the smallpox pathogen? A) They were exposed to dried scabs from smallpox lesions. B) They were exposed to bedding or clothes of a person with smallpox. C) Babies were nursed by women who had already had smallpox. D) They were exposed to a bovine version of the disease, which is mild in humans. E) They were placed in a room with a person who currently had smallpox.

2) The technique of vaccination as developed by Jenner was an improvement over variolation because A) the cowpox virus used by Jenner was not fatal to humans but provided protection against smallpox. B) cowpox was common in Europe at the time while smallpox was not. C) the smallpox virus mutates frequently but the cowpox virus does not. D) Jenner's technique required a lower rate of herd immunity to prevent the spread of smallpox. E) cowpox vaccination was not just preventative but could also cure an active case of smallpox.

3) A major factor in the re-emergence of vaccine-preventable diseases in the early 21st century has been A) a flawed research study incorrectly linking vaccination to autism was published in the late 1990s. B) concerns about animal rights have led people to avoid pharmaceuticals and other products that might have been tested on animals. C) fears of biological weapons after the September 11, 2001 terrorist attacks turned public sentiment against vaccines. D) microbes can develop resistance to vaccines just as they to do antibiotics. E) a flawed research study incorrectly linking vaccination to breast cancer was published in the late 1990s.

4) The aspect of the immune response that vaccines are based on is A) stimulation of cellular, as opposed to humoral, immunity. B) protection of the normal microbiota. C) inflammation and fever. D) stimulation of phagocytosis. E) production of memory cells and high antibody titers from pathogen exposure.

5) Herd immunity describes A) the protection conferred to non-immunized people when a sizable portion of the rest of the population is immunized. B) the social phenomenon of vaccine refusal reinforced by internet memes and social media C) the process of immunizing animals so that people do not acquire zoonotic diseases. D) the process of spacing out vaccinations in infants to just one per doctor's visit. E) the temporary immunity an infant receives from its mother during gestation and from breastfeeding.

6) In the figure, gray figures represent non-immune individuals; black figures represent immune individuals. Which population will be least likely to experience disease outbreak?

A) Population 1 B) Population 2 C) Population 3 D) None of the populations E) All of the populations

7) Live attenuated vaccines A) are closest to the actual infectious agent encountered in nature and require the use of an adjuvant. B) require the use of an adjuvant. C) stimulate potent immune responses to multiple antigens on the pathogen. D) are the closest to the actual infectious agent encountered in nature and stimulate potent immune responses to multiple antigens on the pathogen. E) are the closest to the actual infectious agent encountered in nature.

8) Conjugate vaccines which link the target antigen to a more immunogenic antigen are usually for A) vaccines against bacterial exotoxins. B) vaccines against viral envelopes. C) vaccines against Gram-negative endotoxin. D) vaccines against viral nucleic acid. E) vaccines against bacterial polysaccharide antigens.

9) A drawback of all inactivated vaccines is that A) they are quickly cleared from the body, limiting antigen exposure. B) they may mutate to a more virulent form. C) they are likely to cause disease in immunocompromised hosts. D) they require complex genetic engineering techniques to produce. E) they may cause secondary transmission from the immunized person to another host.

10) A vaccine additive which enhances the body's natural immune response is called a(n) A) recombinant. B) adjuvant. C) toxoid. D) booster. E) attenuant.

10)

11) Adjuvants appear to work by A) stimulating isotype-switching in B cells and cytokine release. B) stimulating isotype-switching in B cells. C) stimulating cytokine release and encouraging the uptake and processing of antigens by dendritic cells. D) encouraging the uptake and processing of antigens by dendritic cells. E) stimulating cytokine release.

11)

12) A DNA vaccine involves placing genes into a plasmid and introducing the plasmid into human cells. Human cells then transcribe and translate the genes to produce antigen which immunize the recipient. What is the source of the genes being introduced? A) a harmless virus B) a member of the patient's microbiome C) a laboratory animal (such as a mouse) D) a pathogen E) human B or T cells

12)

13) In a recombinant vector vaccine, genetic material from a pathogen is placed into a introduced to human cells. A) human dendritic cell B) harmless virus or bacteria C) human B or T cell D) plasmid vector E) pathogenic virus or bacteria

and

13)

14) Advantages that immunological diagnostics have over biochemical testing include all except A) identification of past exposure to a pathogen, not just a current infection. B) identification of both cellular and viral pathogens. C) identification of organisms that cannot be cultured in the lab. D) faster completion times. E) detection of an organism that has not been previously identified.

14)

15) Agglutination tests make use of the fact that A) a reporter enzyme can be bound to an antibody to provide a visual change with a positive test. B) antibodies bound to antigen will precipitate in a gel matrix. C) T cells will release interferon-gamma during certain infections. D) antibodies have two antigen-binding sites and will cause clumping when bound to antigen. E) the presence of antibodies in a patient's serum will prevent viral infection of cells in culture.

15)

16) According to the agglutination tests pictured below, what is the blood type of the sample being teste

16)

A) A B) B C) AB D) O E) Could be either A or B

17) A radial immunodiffusion test is helpful for A) quantifying the amount of different antibody isotypes in a sample. B) quantifying the amount of an antigen or of diverse antibody isotypes in a sample. C) quantifying the amount of an antigen or of diverse antibody isotypes in a sample, or testing the patient's serum for diverse antigens. D) quantifying the amount of an antigen present in a sample. E) testing the patient's serum for diverse antigens.

17)

18) Plaque reduction neutralization tests are based on the fact that A) T cells will release interferon-gamma during certain infections. B) the presence of antibodies in a patient's serum will prevent viral infection of cells in culture. C) antibodies bound to antigen will precipitate in a gel matrix. D) antibodies have two antigen-binding sites and will cause clumping when bound to antigen. E) a reporter enzyme can be bound to an antibody to provide a visual change with a positive test.

18)

19) The plaque reduction neutralization test (PRNT) is preferred over other methods mainly because A) PRNT can differentiate between closely related viruses which have similar antigens. B) working with the live pathogens required for PRNT is risky. C) it is faster than most other methods. D) PRNT can detect low-levels of antibody. E) PRNT does not require working directly with a patient blood sample.

19)

20) In a direct ELISA, the reporter enzyme A) reacts directly with the antigen the assay is seeking. B) reacts directly with the antigen the assay is seeking and chemically modifies an added substrate to generate a colorimetric or chemiluminescent change. C) is bound to the detection antibody and chemically modifies an added substrate to generate a colorimetric or chemiluminescent change. D) is bound to the detection antibody. E) chemically modifies an added substrate to generate a colorimetric or chemiluminescent change.

20)

21) Compared to a direct ELISA, a sandwich ELISA A) does not depend on a reporter enzyme. B) can be designed to be read without a plate reader, making it suitable for home use. C) only requires the use of one antibody. D) is less sensitive. E) does not require unbound antibody to be washed away.

21)

22) An indirect ELISA is pictured. In which step is the detector antibody added to the assay?

22)

A) step 1 B) step 2 C) step 3 D) step 4 E) steps 3 and 4 23) While performing an ELISA, a lab technician fails to rinse away unbound detection antibody from the wells before adding the substrate for the reporter enzyme. What is the likely outcome of this error? A) The test results will not be affected. B) The control wells will indicate a negative result, but the wells with the test sample will indicate a positive result. C) All wells, including controls, will indicate a negative result. D) All wells, including controls, will indicate a positive result. E) The outcome cannot be determined from this information.

23)

24) How does immunofluorescence microscopy detect rabies in brain tissue of an infected animal? A) Fluorescent-tagged antibodies provide light needed to see the virus particles in the microscope. B) Fluorescent-tagged antibodies bind to the antibodies generated to fight the infection. C) Fluorescent-tagged antibodies bind to cytotoxic T cells that are attempting to kill infected cells in the tissue. D) Rabies virus naturally fluoresces under ultraviolet light. E) Fluorescent-tagged antibodies bind to rabies antigen in the tissue and are visible in a specialized microscope.

24)

25) The interferon-gamma release assay for tuberculosis infection works because A) one can perform an indirect ELISA to detect antibodies to interferon-gamma in a patient with TB. B) the T cells of an infected person release more interferon-gamma than that of a non-infected person. C) individuals who have had the TB vaccine can be identified by the amount of interferon-gamma in their blood. D) the presence of interferon-gamma indicates a person is susceptible to TB infection. E) the TB bacterium releases interferon-gamma.

25)

26) Advantages of the interferon-gamma release assay (IGRA) over the traditional TB skin test include all of the following except A) IGRA only detects active TB infections. B) IGRAs are sensitive enough to detect early cases of TB. C) IGRA can provide results within a day. D) IGRA requires only one patient visit as opposed to two with the skin test. E) IGRA can be used on persons who have been vaccinated against TB.

26)

27) Which aspect of the polymerase chain reaction (PCR) is mismatched with its description? A) template DNA: the DNA to be copied; must be present at a high concentration for the procedure to work B) variable temperatures: the highest temperature required for double-stranded DNA separation, the lowest temperature to allow primers to anneal, and a midrange-temperature for DNA replication C) DNA primers: sequences specifically chosen to be complementary to the DNA which flanks a target gene or region of interest D) Taq polymerase: a DNA-replication enzyme which functions at high temperatures E) dNTPs: building blocks of DNA

27)

28) Reverse transcription PCR is used specifically to A) measure how many copies of a specific gene are in a sample. B) detect the presence of RNA viruses. C) perform PCR at cooler temperatures. D) detect the presence of gene expression in a gives cell. E) replace a mutated gene with a corrected gene.

28)

29) The correct order of steps to follow when using recombinant DNA technology to produce a protein for pharmacological use is A) transform host cells with the expression vector — grow the transformed cells into suitable quantities — isolate the desired gene — insert the gene into an expression vector — purify the expressed protein. B) isolate the desired gene — purify the expressed protein — grow the transformed cells into suitable quantities — insert the gene into an expression vector — transform host cells with the expression vector. C) isolate the desired gene — insert the gene into an expression vector — transform host cells with the expression vector — grow the transformed cells into suitable quantities — purify the expressed protein. D) purify the expressed protein — insert the gene into an expression vector — transform host cells with the expression vector — grow the transformed cells into suitable quantities — isolate the desired gene. E) grow the transformed cells into suitable quantities — transform host cells with the expression vector — insert the gene into an expression vector —isolate the desired gene — purify the expressed protein.

29)

30) Recombinant DNA technologies are most often used for A) genetic screening of newborns for inherited diseases. B) creating billions of copies of a target gene in a few hours, measuring expression levels of a gene in a particular cell, producing large amounts of a particular protein quickly and easily, and genetic screening of newborns for inherited diseases. C) measuring expression levels of a gene in a particular cell. D) producing large amounts of a particular protein quickly and easily. E) creating billions of copies of a target gene in a few hours.

30)

31) Which enzyme is used to generate compatible sticky ends in order to join a desired gene to a plasmid vector in recombinant DNA techniques? A) reverse transcriptase B) CRISPR-Cas9 C) restriction enzymes D) DNA ligase E) Taq polymerase

31)

32) The CRISPR-Cas9 system uses all except which of the following? A) an enzyme to cut both strands of DNA at the target site B) prokaryotic or eukaryotic cells to be edited C) replacement DNA to be inserted at the cut site D) reverse transcriptase enzyme E) a guide RNA which locates the gene to be edited

32)

33) In order to successfully and safely deliver a gene to a human cell, a virus vector must be A) pathogenic but not infectious. B) a retrovirus. C) packaged with RNA rather than DNA. D) both infectious and pathogenic. E) infectious but not pathogenic.

33)

34) Genome mapping A) documents the position of every nucleotide. B) documents the position of every nucleotide and provides a blueprint for the proteins and regulatory RNAs produced by a cell. C) may reveal the presence of "pathogenicity islands" as well as information about genes for basic cellular functions. D) provides a blueprint for the proteins and regulatory RNAs produced by a cell. E) documents the position of every nucleotide, provides a blueprint for the proteins and regulatory RNAs produced by a cell, and may reveal the presence of "pathogenicity islands" as well as information about genes for basic cellular functions.

34)

35) DNA microarrays reveal A) if reverse transcriptase is present in a given cell. B) if any genes are mutated in a given cell. C) which genes are found in a given cell. D) which genes are being expressed in a given cell. E) if a particular gene was acquired via horizontal gene transfer.

35)

36) A genetics-based test which would help physicians determine whether a given a cancer will recur, or what types of chemotherapy or radiation therapy treatments would be most successful would be A) CRISPR-Cas9. B) genome mapping. C) DNA microarray. D) recombinant DNA techniques. E) real-time PCR.

36)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 37) Vaccines are only necessary for infants and children.

37)

38) The more closely a vaccination agent resembles the actual infectious agent, the more likely a strong adaptive immune response will be elicited.

38)

39) The risk of a vaccine for an immunocompromised individual is higher for inactivated vaccines than for live attenuated vaccines.

39)

40) Immunological diagnostic tests are based on the fact that a given antibody will bind only with a specific antigen.

40)

41) A plaque reduction neutralization assay is performed with a patient serum. The presence of abundant plaques on the plate indicates that the patient is currently infected with the virus in question.

41)

42) A direct ELISA is most useful for detection of antigens while an indirect ELISA is used to determine if a patient has a particular type of antibody in their blood.

42)

43) Polymerase chain reaction (PCR) techniques can detect the presence as few as a single viral particle in a sample.

43)

44) The CRISPR-Cas9 gene editing system so far can only be used to alter prokaryotic cells.

44)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 45) Describe the different vaccine types, and the advantages and disadvantages of each. 46) Describe the principles of ELISA and contrast the three types. 47) Describe how the polymerase chain reaction (PCR) works and discuss its applications.

Answer Key Testname: UNTITLED28

1) A 2) A 3) A 4) E 5) A 6) B 7) D 8) E 9) A 10) B 11) C 12) D 13) B 14) E 15) D 16) B 17) D 18) B 19) A 20) C 21) B 22) C 23) D 24) E 25) B 26) A 27) A 28) B 29) C 30) D 31) C 32) D 33) E 34) E 35) D 36) C 37) FALSE 38) TRUE 39) FALSE 40) TRUE 41) FALSE 42) TRUE 43) TRUE 44) FALSE

Answer Key Testname: UNTITLED28

45) Currently available vaccines are categorized on whether the vaccine agent is active (live) or inactive. Live vaccines contain a microbe that are infectious but not pathogenic, a condition known as attenuated. Live attenuated vaccines stimulate potent immunological responses, long-lived memory, and activation of B and T cells against multiple antigens. Live vaccine agents may rarely mutate to a more virulent form, posing risks to immunocompromised persons especially. These vaccines may have the potential to transmit other agents from the tissue cultures in which they are grown, and may also transmit from the vaccinated individuals to unwitting contacts. Live attenuated vaccines must be refrigerated up until the time of use. Inactivated vaccines may contain whole inactivated pathogens, parts of pathogens, or inactivated toxins. These vaccines risk of infectivity to immunocompromised individuals, but they are cleared quickly from the body, so multiple doses ar for full immunity to develop and be maintained. Whole-agent inactivated vaccines contain the entire pathogen which h been treated with heat, chemicals, or radiation. Subunit vaccines contain select purified antigens from the pathogen, and may be harvest from the pathogen itself or manufactured using recombinant DNA technologies. Toxoid vaccines contain inactivated toxins so that the protection is to the bacterial toxin and not the bacteria itself. Conjugate vaccines contain polysaccharide antigens such as bacteria capsules. Because polysaccharides are poorly immunogenic on their own, these molecules are conjugated to more immunogenic protein molecules. A third category of vaccines based on DNA technologies include DNA vaccines and recombinant vector vaccines. These vaccines introduce pathogen DNA into selected host cells. The genes are transcribed and translated in the patient's own cells, and when secreted or displayed on the cell surface, stimulate an immune response. These vaccines are currently in the experimental stage. 46) Enzyme-linked immunosorbent assays (ELISAs) are widely-used diagnostic tests. ELISA relies on the specific interaction between an antibody and the antigen it binds to. All variations of ELISA use a reporter enzyme linked to a detection antibody. The detection antibody binds to its specific antigen (which sometimes is another antibody). After unbound antibody is removed by washing, the chemical substrate for the reporter enzyme is added. Typically, the enzyme-substrate pair is chosen to generate a colorimetric or chemiluminescent reaction which can be visually observed or detected with a device called a plate reader. ELISAs can be run in bulk in 96-well plates or can be designed in a variety of single-use devices such as a home pregnancy test or the "rapid-Strep" used in clinics and doctors' offices. There are three ELISA "formats" but ELISAs can be designed for virtually any antigen, and hundreds of different ELISAs are commercially available. Direct ELISA allows for identification of an antigen in a sample in three basic steps: binding antigens to a well surface, addition of the detector antibody with bound enzyme, followed by the enzyme substrate. Direct ELISA is not recommended for crude samples. Indirect ELISA is often used to detect the presence of a specific antibody in a patient sample. With the indirect ELISA, the antigen is already bound to the plate. The test sample containing unknown antibodies is added, followed by a secondary detection antibody which is designed to bind to the antibody being measured. Finally, the enzyme substrate is added. A sandwich ELISA allows detection of an antigen in a sample but is more sensitive than the direct ELISA. The wells come with a capture antibody already loaded. The patient sample is added, and if the antigen is present, it will bind to the capture antibody. The enzyme-linked detection antibody is added, sandwiching the antigen between the two antibodies. Finally, the enzyme substrate is added. All forms of ELISA depend specifically on the binding of the specific antigen to its antibody. If the antigen being sought is not in the sample, antibody cannot bind and will be washed away prior to the addition of the enzyme substrate.

Answer Key Testname: UNTITLED28

47) The polymerase chain reaction (PCR) technique can detect a specific sequence of DNA in virtually any sample, even if the desired DNA is present in only minute quantities. PCR works by rapidly cycling a sample containing DNA through a series of three temperatures. The first temperature, 95C, separates any double-stranded DNA in the sample. A lower temperature between 50-65C allows added DNA molecules called primers to bind to complementary regions on the DNA in the sample. The primers are specifically chosen to flank the segment of interest on the sample DNA. Once the primers bind, temperature is again shifted to 65-75C. This allows the sample DNA to be replicated between the two primer segments. Replication is accomplished by an added DNA polymerase enzyme (Taq polymerase) which is isolated from a thermophile bacterium. Using a heat-tolerant enzyme allows it to maintain its activity during the high temperatures required for strand separation. Deoxynucleotide triphosphates (dNTPs) are provided to serve as the raw material for DNA synthesis. The cycle then repeats, and both the original DNA and the newly-synthesized DNA strands can serve as templates for the next round of replication. As a result, the number of DNA copies doubles with every cycle, and after a typical run of 30 cycles, one DNA molecule is multiplied to 10 billion copies. The amplified DNA sample is often visualized using gel electrophoresis. A variation called real-time PCR bypasses the need for gel electrophoresis by adding florescence imaging to visualize the DNA as it is being produced (and also allows for quantification). Reverse-transcription PCR allows detection of RNA in a sample by using to reverse transcriptase enzyme to convert the RNA into DNA.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Why did Alexander Fleming suspect he could get penicillin from a species of mold? A) Soldiers drinking fermented alcohol were less likely to have bacterial infections. B) Bacteria on culture plates were unable to grow near mold contamination. C) Patients infected with a fungus like, athlete's foot, were less likely to have bacterial infections. D) Wounds with superficial mold on the bandages were not becoming septic. E) Soldiers eating moldy bread were not suffering from wound infections.

2) Why might broad spectrum antimicrobials be initially used when treating a patient? A) An initial round of broad spectrum antimicrobials increases the efficiency of narrow spectrum antimicrobials. B) They are cheaper to use. C) They may initially be used to protect the patient since it can take several days to make a definitive bacterial identification. D) It's best to start with broad spectrum antimicrobials until patient records are available that show if the patient has any antimicrobial allergies. E) The physician has never encountered that pathogen before.

3) Bactericidal drugs tend to target bacterial A) cell walls, cell membranes, and nucleic acids. B) protein synthesis and nucleic acids. C) cell walls and cell membranes. D) nucleic acids. E) cell walls and enzyme activation.

4) What is the major challenge with developing new synthetic antimicrobials? A) finding the right dose B) choosing which bacterial structure to target C) figuring out if the drug is bacteriostatic or bactericidal D) the need to screen thousands of potential candidates E) deciding what bacteria to test it on

5) An antibiotic is A) a preparation used to sterilize a person or object. B) a chemical that kills or removes bacteria, viruses, protozoa, helminths, or fungi. C) a naturally occurring compound that kills microbes or inhibits their growth. D) a drug which is wholly manufactured by chemical processes. E) medicine that removes pathogenic organisms from the body.

6) A therapeutic index is a ratio between A) patient survivability versus patient allergies. B) patients that benefited from drug versus patients that experienced side effects. C) toxicity versus half-life. D) maximum safe dose versus minimum effective dose. E) potential patients not ruled out due to drug interactions or contraindications versus patients that experienced side effects.

7) Which of the following would pertain to a bad antibiotic? A) no drug interactions

B) low toxicity C) no contraindications D) narrow therapeutic index E) long half-life 8) Which organs are particularly susceptible to damage by certain antimicrobial drugs? A) brain and spleen B) pancreas and gallbladder C) stomach and intestines D) kidneys and liver E) heart and lungs

9) Which of the following is an example of a hepatotoxic drug? A) aspirin B) streptomycin C) gentamicin D) amoxicillin-clavulanate E) vancomycin

10) Which of the following is not a beta-lactam drug? A) monobactam B) quinolone C) carbapenem D) cephalosporin E) penicillin

10)

11) How do glycopeptide drugs differ from beta-lactam drugs? A) Glycopeptide drugs specifically target Gram-negative bacteria. B) Glycopeptide drugs are easily absorbed across the intestines and therefore commonly used as oral preparations against systemic infections. C) Glycopeptide drugs are broad-spectrum drugs, unlike beta-lactamases which are narrow-spectrum drugs. D) Glycopeptide drugs do not have a beta-lactam ring, so they are not susceptible to beta-lactamases. E) Glycopeptide drugs are often found to be ineffective due to antibiotic-resistance.

11)

12) Which of the following is false about quinolones? A) In rare instances, these drugs have been associated with more serious side effects such as nerve damage, tendonitis, and possible tendon rupture. B) They are synthetic antimicrobials that target cell-wall synthesis. C) They are excellent in situations where there isn't time to identify the responsible pathogen. D) The more modern and most commonly prescribed group of quinolones contain a fluorine atom. E) They have a broad spectrum of action, can be taken orally, and have a relatively long half-life.

12)

13) Which of the following is false about rifamycins? A) They were originally isolated from bacteria. B) The drugs are useful to combat mycobacterial species that can be especially tough to treat due to the challenges of getting drugs across their waxy mycolic acid-enriched cell wall. C) Because the chemical structure is such a good fit with RNA polymerase, it is unlikely to cause interactions with any other medications currently known. D) They inhibit transcription by binding to RNA polymerase. E) They are broad-spectrum antimicrobials that are effective against most Gram-positive bacteria and some Gram-negative bacteria too.

13)

14) Why don't sulfa drugs target mammalian cells? A) Mammalian cells do not use folic acid and therefore do not have the enzyme that these drugs target. B) Mammals make their own folic acid but use a completely different substrate to start the process and therefore sulfa drugs are unable to disrupt the process. C) Mammals do not make their own folic acid and therefore do not have the enzyme that these drugs target. D) Sulfa drugs do target mammalian cells but the bacteria die so quickly that the patient experiences mild symptoms but can then stop taking the medication before experiencing any serious symptoms. E) Mammalian cells produce inhibitors to the sulfa drugs.

14)

15) Which of the following antimicrobials does not match its potential shortcomings? A) Macrolides: This narrow-spectrum drug must be administered parenterally. B) Aminoglycosides: Are known to cause irreversible hearing loss when administered other than topically. C) Tetracyclines: Induce photosensitivity, causes detrimental effects on bones and teeth in children younger than 8 years old, and are associated with an increased risk of Clostridium difficile infection D) Phenicols: Has a narrow therapeutic index and is associated with bone marrow toxicity that results in aplastic anemia. E) Lincosoamides: One common lincosoamide is associated with pseudomembranous colitis caused by Clostridium difficile.

15)

16) Which of the following antimicrobials does not match its target? A) lincosoamides: 50S subunit B) phenicols: 50S subunit C) macrolides: 50S subunit D) aminoglycosides: 30S subunit E) tetracyclines: 50S subunit

16)

17) How do polypeptide drugs work? A) They target the 50S subunit of prokaryotic ribosomes to block protein synthesis. B) They act as competitive inhibitors of folic acid production. C) They work by inhibiting transpeptidase enzymes that are central to building peptidoglycan by forming the protein crosslinks that bind peptidoglycan's carbohydrate chains together in a chain link fence-like structure. D) They target the DNA replication enzymes DNA gyrase and topoisomerases. E) They interact with lipopolysaccharide and destabilize the outer membrane of the Gram-negative cell wall where they can then further destabilize the plasma membrane to cause cytoplasmic leakage and cell lysis.

17)

18) Why is it difficult to develop drugs that specifically target viruses and eukaryotic pathogens? A) There are often duplicate metabolic pathways that pick up the slack from any disturbance caused by these drugs. B) Viruses and eukaryotes evolve too rapidly for drugs to be effective. C) The ethical concerns with testing these drugs are too great. D) The drugs often inflict collateral damage on our own cells. E) Security enzymes break down these foreign drugs before they can exert their effects.

18)

19) Which of the following does not make a good target for antiviral drugs? A) viral release B) viral attachment C) viral integration D) viral replication and assembly E) viral penetration

19)

20) Which of the following drugs are not matched correctly with their uses? A) polyenes: cutaneous candidiasis caused by Candida albicans or treating life-threatening systemic fungal infections B) azoles: athlete's foot, ringworm, and yeast infections C) Flucytosine: administered in combination with amphotericin B for severe fungal infections such as Cryptococcus meningitis and systemic Candidiasis infections D) echinocandin drugs: systemic fungal infections in immune-compromised patients E) allyamines: systemic fungal infections like in coccidioidomycosis caused by Coccidioides immitis

20)

21) Which of the following drugs are not matched correctly with their mode of action? A) Flucytosine: targets fungal DNA replication by blocking transcription when it is converted to a nucleic acid analog that blocks DNA and RNA synthesis B) azoles: inhibits ribosome function by entering ribosome as a tRNA, covalently binding to mRNA, and forcing the destruction of the complex C) allyamines: inhibits enzymes that build ergosterol which leads to improperly built plasma membranes and fungal cell lysis D) echinocandin drugs: inhibits fungal cell wall synthesis by targeting an enzyme that makes a component of the fungal cell wall E) polyenes: directly interacts with ergosterols which causes targeted plasma membranes to become leaky and leads to cell lysis

21)

22) Artemisinin-based combination therapies are used to treat A) chronic Toxoplasma gondii infections. B) severe fungal infections such as Cryptococcus meningitis and systemic Candidiasis infections. C) mild to moderate C. difficile infections that don't have complications. D) uncomplicated and severe cases of malaria. E) life-threatening multidrug resistant infections, especially those caused by Pseudomonas aeruginosa, Acinetobacter baumannii, or Klebsiella pneumoniae.

22)

23) What does nitrazoxanide do in order to treat infections with Giardia and Cryptosporidium as well as against certain parasitic worms? A) the mechanisms of action are unclear B) interferes with glucose uptake by targeting microtubules C) paralyzes the protozoans D) targets nucleic acids E) blocks anaerobic energy metabolism in protozoa

23)

24) What is the mechanism of action for the antihelminthic drug praziquantel? A) paralyzes the parasites B) blocks anaerobic energy metabolism in protozoa C) the mechanisms of action are unclear D) interferes with glucose uptake by targeting microtubules E) targets nucleic acids

24)

25) Why is it entirely possible for a pathogen to appear susceptible in susceptibility testing and resistant in a real-life context? A) A person's liver may break down the drug before it even begins to benefit the patient. B) Bacterial levels and active drug concentrations vary from one tissue to another in an active infection. C) A real-life infection allows for the possibility of genetic crossover with different bacteria, whereas tests in the lab are focused on studying a single strain of bacteria. D) The ability of the pathogen to live as part of a biofilm and benefit from the protection of other bacteria does not exist in susceptibility tests. E) An active infection is more likely to mutate due to the larger population.

25)

26) The collected data of a Kirby-Bauer test is often presented in A) a graph. B) an antibiogram. C) a pie chart. D) a bacteriostatic or bactericidal report. E) a minimal inhibitory concentration report.

26)

27) An E-test can reveal A) if a drug is bacteriostatic or bactericidal. B) the minimal inhibitory concentration of a drug. C) the minimum bacteriostatic concentration. D) the minimum bactericidal concentration. E) the mechanism of action for a particular drug.

27)

28) Which of the following drugs demonstrates the most effective minimal inhibitory concentration?

A) 2

B) 4

C) 5

D) 6

28)

E) 9

29) In order to identify the minimum bactericidal concentration in broth dilution tests, what must be determined first? A) how successfully the bacteria grow in broth cultures B) minimal inhibitory concentration C) how many bacteria grow on a plate from each of the broth dilution tests D) minimal bacteriostatic concentration E) drug concentration and bacterial concentration

29)

30) If a superbug is resistant to an antibiotic due to horizontal gene transfer, the microbe is said to have A) intrinsic resistance. B) acquired resistance. C) mutational resistance. D) natural resistance. E) evolutionary resistance.

30)

31) Pseudomonas aeruginosa is one of the most notoriously resistant pathogens. Which of the following mechanisms does this bacteria use to evade antimicrobials? A) efflux pumps B) drug inactivation C) reduced permeability D) target alterations E) This bacteria uses all of the possible ways to evade antimicrobials, which is why it is so good at it.

31)

32) In terms of personal health, why should vegetarians still care about the misuse of antibiotics in livestock? A) Manure-contaminated runoff is destroying aquatic life when this runoff gets into local waterways. B) Food is often cross contaminated but it's better to have an easily treatable GI infection compared to an antibiotic resistant GI infection. C) Manure-contaminated water and manure-based fertilizers introduce resistant bacteria into the food chain. D) Livestock live happier lives without constantly eating antibiotics. E) Recreational water activities become a source of infection when manure-contaminated runoff finds its way into these areas.

32)

33) Which of the following reasons to not take unnecessary antibiotics is false? A) Antibiotics can cause mild side effects like diarrhea, nausea, sunburn, headache, vomiting, and a rash. B) Antibiotics cost money and are time consuming to take. C) Taking unnecessary antibiotics can put you at risk for developing an antibiotic resistant bacterial infection that could be life threatening. D) Antibiotics can cause severe side effects like red man syndrome. E) Antibiotics are not safe to take during pregnancy.

33)

34) Although all of the following microbes are of serious concern, which one is ranked as urgent on the CDC's list of top drug-resistant pathogens? A) Pseudomonas B) Candida C) Clostridium D) Campylobacter E) Mycobacterium

34)

35) Which of the following is not an approach to combat drug-resistant bacteria? A) identify new antimicrobials B) pair a redesigned antimicrobial with inhibitors that block bacterial-resistance mechanisms C) flood a patient's system with healthy bacteria to quickly remove access to nutrients and starve the pathogen D) use lytic bacteriophages to specifically target pathogens E) find multidrug approaches

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) A patient with bacterial meningitis will be given a bacteriostatic antibiotic, as well as an anti-inflammatory steroid.

36)

37) Nephrotoxic antimicrobial drugs can induce liver damage and are leading agents of drug-induced liver injury.

37)

38) When combating methicillin- and oxacillin-resistant Staphylococcus aureus strains, it is effective to administer alternative beta-lactam drugs.

38)

39) Combination therapy uses two or more drugs in combination to decrease the likelihood that a pathogen will survive the therapy due to drug resistance.

39)

40) If two drugs target different steps of the same biochemical pathway, when used together, these two drugs tend to exhibit synergism.

40)

41) Trimethoprim-sulfamethoxazole is an antifolate drug combination that works by blocking folate production in certain bacteria as well as in certain protozoans.

41)

42) Although protozoan parasites develop drug resistance, it's difficult and time consuming to test them for their drug response, which means the prescribed therapy tends to use a trial-and error approach.

42)

43) Clostridium difficile naturally form endospores that inherently resist most antibiotics due to their dormant nature and their tough spore coat that blocks drug entry.

43)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 44) Why is there not a clinical distinction between bacteriostatic and bactericidal antibiotics? 45) In what ways are humans affected by agricultural practices that promote bacterial resistance? 46) Explain what ECE stands for and how it can help you to say no to a patient requesting a prescription for antibiotics.

Answer Key Testname: UNTITLED29

1) B 2) C 3) A 4) D 5) C 6) D 7) D 8) D 9) D 10) B 11) D 12) B 13) C 14) C 15) A 16) E 17) E 18) D 19) C 20) E 21) B 22) D 23) E 24) A 25) B 26) B 27) B 28) E 29) B 30) B 31) A 32) C 33) E 34) C 35) C 36) FALSE 37) FALSE 38) FALSE 39) TRUE 40) TRUE 41) TRUE 42) TRUE 43) TRUE 44) An antimicrobial drug that is bactericidal for one pathogen may be bacteriostatic for another. Furthermore, a drug's bactericidal or bacteriostatic properties can change based on the drug dose, length of the drug regimen, pathogen load, and route of administration.

Answer Key Testname: UNTITLED29

45) Although the U.S. Food and Drug Administration (FDA) has banned adding antimicrobials used in human medicine to animal feed for growth promotion purposes, the FDA still allows antimicrobials that are not approved for human use to be used as livestock growth enhancers. While this may seem like a way to prevent resistance to clinically useful antimicrobials, it is not necessarily a safe bet. Drugs used for animals have been documented to induce cross-resistance to human antibiotics. Resistant strains can then be introduced into humans through meat, the environment, animal handling, or through vegetable crops that are fertilized with manure or watered with reclaimed water that may be manure contaminated. 46) Empathy: Make it clear to your patient that you care about her, that you want to do the best thing for her short- and longer-term medical wellbeing, and that you know she is suffering and longing for relief. Take a moment to recall the last time you felt miserable and desperate to feel better. Share that feeling with her. Competence: Help your patient feel confident in your competence. Give her a peek into the systematic thought process that led to the diagnosis. Try to infuse some information about how viral and bacterial infections can be differentiated and share what features make it clear that she has a viral infection. Education: Close the "no" conversation with some education about antibiotics. Explain that antibiotics don't cure viral infections; they may cause adverse side effects like diarrhea and nausea that may be just as unpleasant as a cold, and that if used unnecessarily they could be ineffective when they are really needed. Let your patient know that if her condition worsens or she develops new symptoms, you are there to help and will adjust the care plan as needed to best protect her health.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The upper respiratory tract is lined with mucous membranes which secrete mucous. What is the purpose of mucous? A) cools and dries the air we breathe B) warms and humidifies, and traps microbes and debris from the air we breathe C) cools and dries, and traps microbes from the air we breathe D) warms and humidifies the air we breathe E) traps microbes and debris from the air we breathe

2) Which component of the lower respiratory tract is incorrectly matched with a function or description? A) bronchi: direct air to the lungs B) alveoli: site of gas exchange C) lungs: contain the alveolar sacs D) larynx: contains the mucociliary escalator E) bronchioles: have ciliated mucous membranes

3) Infection in the respiratory tract is limited by all except A) the epiglottis sealing the airway during swallowing. B) coughing to bring microbes away from the lungs. C) alveolar macrophage. D) resident microbiota. E) ciliated mucous membranes.

4) Which statement is not true about the resident microbiota of the respiratory tract? A) Smoking affects the numbers and types of species in the microbiota. B) The lungs have recently been found to contain a resident microbiome that resembles that found in the mouth. C) Microbiota are only found in the upper respiratory tract. D) Resident microbiota secrete antimicrobial peptides and compete with pathogens. E) The resident microbiota of a healthy person is limited to just a few species of bacteria.

5) Pneumonia is A) wheezing or loud breathing associated with airway obstruction. B) inflammation of the entire lower respiratory tract except the lungs. C) rapid swelling of the airway that can block breathing. D) shortness of breath. E) inflammation of the alveoli which interferes with gas exchange.

6) A life-threatening bacterial infection that results in complete blockage of the airway due to swelling of a flap of tissue that normally protects the lungs during swallowing is A) hay fever. B) dyspnea. C) epiglottitis. D) stridor. E) croup.

7) A two-year-old child presents to a pediatric practice with a barking cough and loud wheezing. The parent is alarmed and insists on antibiotics. What is the likely diagnosis, and are antibiotics appropriate? A) allergies / no, allergies are caused by irritants and are not infections B) sinusitis / no, most cases are due to viral infections or irritants C) croup / no, most cases are viral D) epiglottitis / yes, this is a life-threatening bacterial infection E) pneumonia / yes, this can be a life-threatening condition and is often bacterial

8) Vaccine prevention of acute respiratory infections (the common cold) is unlikely because A) humans do not generate a strong immune response to common cold viruses. B) there are many distinct virus strains and serovars that cause the common cold. C) there is a relatively low social and economic cost associated with the common cold. D) colds are easily misdiagnosed as something else. E) antibiotics easily cure the common cold.

9) Influenza differs from the common cold in that A) it can cause seasonal outbreaks. B) it has a greater fatality rate. C) it is not treatable with antivirals. D) you can get only get influenza once. E) the virus is not subject to mutation.

10) The demographic most at risk from respiratory syncytial virus are A) smokers. B) immunocompromised individuals. C) young children. D) pet owners. E) the elderly.

10)

11) Although each of the following viral groups causes acute respiratory illnesses, associated with conjunctivitis, gastroenteritis, or cystitis. A) influenzas virus B) coronavirus C) respiratory syncytial virus D) human parainfluenza virus E) adenovirus 12) Influenza A strains are characterized by A) whether or not humans are infected. B) the type of animal in which the strain originated. C) the type of HA and NA spikes found on the viral surface. D) whether the virus contains DNA or RNA. E) the country in which the strain originated.

can also be

11)

12)

13) An unusual feature of the 1918 Spanish influenza pandemic is that A) most fatalities were among young adults, rather than infants or the elderly. B) it originated in Europe, most fatalities were among young adults, and victims had unusually poor immune responses. C) it originated in Europe, rather than Asia as most influenza strains do. D) most fatalities were among young adults, and victims had unusually poor immune responses to the virus. E) victims had unusually poor immune responses to the virus.

13)

14) SARS is caused by a(n) A) paramyxovirus. B) adenovirus. C) coronavirus. D) rhinovirus. E) influenza virus.

14)

15) A contributing factor to the spread of the SARS virus during the initial 2003 outbreak was A) transmission of the virus in healthcare settings. B) high smoking rates in Asia. C) similarity to 1918 influenza outbreak. D) air pollution in crowded urban environments. E) global air travel.

15)

16) A 21-year-old male is admitted to the hospital in severe respiratory distress. Despite care, he died of rapid pulmonary edema within 12 hours of admission. Family members report that he had recently started work at a nearby state park. He was on a detail to clean out and renovate a group of rodent-infested rental cabins. Based on the information, what is the likely diagnosis? A) influenza H1N1 B) hanta pulmonary syndrome C) human parainfluenza virus infection D) respiratory syncytial virus E) SARS

16)

17) A key factor in the high prevalence of otitis media in children is A) children are more likely to suffer from colds and influenza than adults. B) the lack of a mature microbiome in the auditory canal. C) the maturing of the innate and adaptive immune responses in children. D) the orientation of the eustachian tube in children prevents efficient fluid drainage. E) children do not complete their routine vaccine schedule until adolescence.

17)

18) This disease is caused by strains of Streptococcus pyogenes which produce an erythrogenic toxin due to the presence of a lysogenized bacteriophage. A) bacterial pneumonia B) rheumatic fever C) scarlet fever D) streptococcal pharyngitis E) necrotizing fasciitis

18)

19) A child with no known congenital problems is diagnosed with inflammation of the heart valves. The medical history of the child is unremarkable except for a sore throat and fever six weeks prior, which the parents attributed to a common cold. The heart valve inflammation is most likely due to A) Bordetella pertussis. B) Corynebacterium diphtheriae. C) autoimmune complications of Streptococcus pyogenes. D) atypical pneumonia. E) tuberculosis.

19)

20) The development of a pseudomembrane on the tonsils and throat is characteristic of A) pertussis. B) tuberculosis. C) diphtheria. D) pneumococcal pneumonia. E) streptococcal pharyngitis.

20)

21) Pertussis is characterized by A) severe coughing attacks where the patient struggles to catch their breath. B) a pneumonia-like infection acquired from air conditioning or water systems. C) high prevalence among those who handle birds. D) a positive tuberculin skin test. E) a high fever with a bright red rash across the body.

21)

22) Recent reemergence of pertussis is due in part to A) ease of global travel. B) waning immunity in adolescents and adults from the short-lived DTaP vaccine. C) reactivation of latent infections in older individuals. D) increased human contact with animal reservoirs. E) increased antibiotic resistance.

22)

23) Latent tuberculosis A) accounts for only a small minority of cases. B) is easily spread through respiratory droplets. C) will result in a negative tuberculin skin test. D) results when M. tuberculosis bacteria are phagocytized and effectively walled off within granulomas in the lungs. E) will eventually progress to active TB in most individuals.

23)

24) The infectious agent that causes tuberculosis is A) unpasteurized milk. B) avian influenza virus. C) one of several Gram-negative bacterial species. D) an acid-fast bacterium of the genus Mycobacterium. E) HIV.

24)

25) A diagnostic sign of typical pneumonia is consolidation which A) is a granuloma walling off infected phagocytes in the lungs and appears as a clear region on a chest X-ray. B) is fluid rather than air in the alveoli. C) is fluid rather than air in the alveoli and appears as a clear region on a chest X-ray. D) appears as a clear region on a chest X-ray. E) is a granuloma walling off infected phagocytes in the lungs.

25)

26) An elderly patient with no recent hospitalizations presents with shortness of breath, chest pain, a deep productive cough, and evidence of consolidation. Acid-fast and Gram stains are performed on a sputum sample. No acid-fast bacteria are detected but Gram-negative, non-encapsulated bacteria are observed. A likely diagnosis is A) influenza. B) nontypable Hemophilus influenzae B. C) Legionnaire's disease. D) Streptococcus pneumoniae. E) Mycobacterium avium.

26)

27) The most common cause of atypical pneumonia, Mycoplasma pneumoniae, has all the following characteristics except A) one of the smallest self-replicating organisms known. B) difficult to see with a standard light microscope. C) a parasitic lifestyle inside host cells. D) contains more genes than most other bacteria. E) no cell wall.

27)

28) A wildlife biologist might be more likely than the average person to contract which types of atypical pneumonia? A) Q fever, psittacosis, and tularemia B) walking pneumonia, chlamydophila pneumonia, and Legionnaire's disease C) Legionnaire's disease and Q fever D) tularemia, chlamydophila pneumonia, and psittacosis E) Legionnaire's disease and psittacosis

28)

29) Which of the following is not a factor in increased incidence of fungal infections? A) climate change B) increasing antibiotic resistance C) increasing number of people living with immunosuppression D) deforestation E) urban development

29)

30) Endemic mycoses are A) due to changes in the patient's normal microbiota. B) easily transmitted person-to-person. C) unable to establish infections in healthy people. D) caused by species who inhabit multiple ecological niches. E) restricted to a specific geographic location.

30)

31) A fungal species which can grow in varied climates and under diverse conditions is termed A) microbiotic. B) normal. C) endemic. D) ubiquitous. E) mycosis.

31)

32) An endemic fungal infection that is found in the semi-arid to dry soils in the southwestern United States and Mexico is A) blastomycosis. B) histoplasmosis. C) murcomycosis. D) coccidioidomycosis. E) aspergillosis.

32)

33) Histoplasmosis should be suspected in cases of fungal respiratory infections found in A) dog owners. B) the Mississippi and Ohio River valley regions. C) HIV-AIDS patients. D) construction workers. E) cattle or dairy farm workers.

33)

34) In an immunocompromised patient with pulmonary or rhinocerebral invasive fungal disease, suspect A) murcomycosis. B) pneumocystis pneumonia. C) either aspergillosis or murcomycosis. D) either aspergillosis, murcomycosis, or pneumocystis pneumonia. E) aspergillosis.

34)

35) Which statement does not apply to pneumocystis pneumonia and its causative organism, Pneumocystis jirovecii? A) Like all other pathogenic fungi, the reservoir is soil. B) The fungus does not make spores. C) Serological evidence suggests that most people are exposed to the organism in early childhood. D) The organism has some characteristics found in protozoans rather than fungi. E) HIV-AIDS patient are high-risk for this infection.

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) A healthy respiratory microbiome is dominated by species from the phyla Bacteroides, Firmicutes, and Proteobacteria.

36)

37) Sinusitis is routinely treated with antibiotics, which is appropriate because most cases are due to bacterial infections.

37)

38) In most individuals, symptoms of the common cold and of influenza are virtually impossible to tell apart in severity.

38)

39) To date, only zoonotic strains of hantavirus have been detected.

39)

40) Vaccination against diphtheria is a toxoid vaccine against inactivated toxin, therefore, the prevalence of asymptomatic carriers of Corynebacterium diphtheriae may be high even as prevalence of the disease itself is low.

40)

41) A positive tuberculin skin test definitively indicates the presence of an active tuberculosis infection.

41)

42) Mycoses are becoming more common due to changes in the patient population, such as immunosuppression, as well as environmental and ecological changes.

42)

43) Endemic fungal infections are most likely to occur in immunocompromised patients while ubiquitous fungal infections are routinely found in otherwise healthy individuals.

43)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 44) Describe the anatomical and physiological features of the respiratory system that limit the establishment of pathogenic organisms. 45) Describe the progression of infection in latent vs. active tuberculosis along with diagnostic criteria and treatment options. 46) Contrast endemic and ubiquitous fungal infection, and describe two examples of each type.

Answer Key Testname: UNTITLED30

1) B 2) D 3) A 4) C 5) E 6) C 7) C 8) B 9) B 10) C 11) E 12) C 13) A 14) C 15) E 16) B 17) D 18) C 19) C 20) C 21) A 22) B 23) D 24) D 25) D 26) B 27) D 28) A 29) B 30) E 31) D 32) D 33) B 34) C 35) A 36) TRUE 37) FALSE 38) FALSE 39) FALSE 40) TRUE 41) FALSE 42) TRUE 43) FALSE

Answer Key Testname: UNTITLED30

44) When air enters the upper respiratory tract, it passes through the paranasal sinus cavities. These cavities are lined with mucous membranes which secrete mucous to trap microbes and debris. The mucous is swept toward the nose and mouth for expulsion by cilia, hair-like projections lining the airway. In the pharynx, the epiglottis is a cartilage structure that seals the entry to the lower respiratory tract while swallowing, preventing the entry of food, beverages, and associated microorganisms to the lungs. The lower respiratory tract airways which include the trachea, bronchi, and bronchioles are lined with ciliate mucous membranes which trap microbes and debris and sweep them upward away from the lungs. This is called the mucociliary escalator. Respiratory infection symptoms such as a runny nose, cough, and sneezing help to expel pathogens but also provide a means for the pathogen to move to the next host. The respiratory tract has an abundant microbiome, even in the lungs. Microbiome members may prevent the establishment of pathogens by competing with pathogens for space and producing antimicrobial peptides. 45) Tuberculosis (TB) is a highly communicable bacterial disease spread by respiratory droplets. Despite a high global incidence and easy transmission, the vast majority of TB cases remain latent. In latent TB, inhaled bacteria are engulfed by phagocytes in the lungs. Some bacterial cells can survive inside the macrophage; however, these infected macrophages are detected by the immune system a walled off within a fibrous granuloma. Approximately 90% of such cases will remain latent for the rest of the patient's lifetime. The remaining cases will progress to active TB at some point in the future. Active TB develops when the center of the granuloma liquifies and breaks down, allowing bacteria to spread to other parts of the lung or other organs, and be transmitted to others. The most common screening test for TB is the tuberculin skin test; however, it can only show past exposure through infection or vaccination and cannot distinguish between active and latent TB. Interferon gamma assays and Xpert MTB/RIF likewise cannot differentiate active and latent TB. Culturing and microscopy of the acid-fast bacterium can detect active TB but not latent. A chest X-ray can be used on a patient who tests positive through a screening method and may detect lung damage due to active TB. Latent TB is treated with rifampin and/or isoniazid for 4 — 9 months. Active TB requires treatment with multiple antibiotics from 6 months to two years depending on the antibiotic-resistance profile of the strain involved. 46) Fungi termed endemic have specific climate and soil condition needed for their growth and are restricted to specific geographic areas. These infections may impact any person who inhales fungal spores. Ubiquitous fungi are widely distributed ecologically and geographically, and may even be members of the normal human microbiome. Ubiquitous fungal infections are also acquired when fungal spores are inhaled, but are generally a danger only to immunocompromised patients. Specific endemic fungal infections include blastomycosis, coccidioidomycosis, and histoplasmosis. Blastomycosis (Blast dematitidis) is found in the Ohio and Mississippi River valleys, the Great Lakes and the St. Lawrence seaway regions. The fungus thrives in soils with decomposing plant matter and become airborne by digging, wood clearing, or construction. Treatment is available, but the infection has a 40% mortality rate in immunocompromised patients. Coccidioidomycosis (Coccidioides immitis and C. posadasii) is also called Valley fever and is found in the semi-arid and dry areas of the southwestern United States, northern Mexico, and Central and South America. In the lungs, the fungi form multinucleated structures called spherules which contain fungal endospores. When the spherules rupture, the endospores are released and cause lung damage. Histoplasmosis (Histoplasma capsulatum) thrives in soil enriched with bird or bat droppings. The fungus is global but concentrated in the Ohio and Mississippi River valleys. Workers who ar exposed to droppings are at greatest risk for infection, and immunocompromised patients are mostly likely to develop t disseminated, systemic form of the disease. Three common ubiquitous fungal infections include aspergillosis, murcomycosis, and pneumocystis pneumonia (PCP). people are exposed to aspergillus spores (Aspergillus fumigatus) on a routine basis; organ transplant patients and chemotherapy or corticosteroid recipients are most at risk to develop invasive disease, of which pulmonary and rhinocerebral are the most common forms. Murcomycosis (Rhizopus arrhizus) is found in soil enriched with rotting wood material. Invasive forms also include pulmonary and rhinocerebral disease. PCP (Pneumocystis jirovecii) is found in AIDS patients and others who are severely immunosuppressed. This fungus is not found in soil but probably is spread by asymptomatic human carriers. Preventative and treatment medications are available; untreated cases have a 100% fatality rate while treatment lowers mortality to 40%

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The presence of , a waterproofing protein, in epidermis prevents many microorganisms from gaining access to the body. A) melanin B) lysozyme C) antibiotics D) keratin E) sebum

2) Why is perspiration an effective defense against microorganisms? A) basic pH, low salt content, and presence of lysozyme B) basic pH C) presence of lysozyme D) basic pH and low salt content E) low salt content

3) Which factor may influence the specific types of microbes found on the skin? A) soap and cosmetics usage B) moisture levels C) hormones, moisture levels, and soap and cosmetics usage D) moisture levels and soap and cosmetics usage E) hormones

4) Which primary skin lesion is incorrectly matched with its description? A) Macule: Flat, discolored area of the skin B) Cyst: Closed fluid-filled sac deep in skin C) Vesicle: Elevated lesion with clear fluid D) Pustule: Raised lesion with pus below the surface E) Papule: Sore of irregular size and shape that results as epidermal and dermal skin layers are destroyed

5) These two secondary lesions arise when bleeding or burst capillaries occur in the skin. A) cysts and ulcers B) crust and scale C) papular and maculopapular rashes D) petechiae and purpura E) bullae and vesicles

6) Which factor, beginning in 1995, is responsible for the decline in chicken pox from a routine childhood disease to a rare infection? A) natural evolution of the virus to a less virulent form B) changes in global migration patterns C) ecological changes affecting the natural reservoir of the virus D) development of effective anti-viral medications E) routine vaccination

7) Which virus results in shingles when it is reactivated with peripheral nerves? A) varicella-zoster B) HSV-1 C) rubella D) rubeola E) variola major

8) Which statement describes an important similarity between chickenpox and smallpox? A) Both involve the formation of a vesicular rash. B) Both are treatable with antiviral therapy. C) Both have a similar mortality rate of about 30%. D) Both are caused by viruses which lie dormant in nerve cells and be reactivated later in life. E) Vaccinations against both are recommended for all children.

9) Which is not a specific cause of reactivation of HSV-1? A) menstruation B) hormonal changes C) stress D) having a cold or fever E) ultraviolet radiation

10) A maculopapular rash is characteristic of A) chickenpox. B) chickenpox and warts. C) warts. D) measles. E) measles and chickenpox.

10)

11) A parent calls the pediatrician's office about uncomfortable sores on the inside of her child's mouth. You suspect hand, foot, and mouth disease (HFMD), but need to rule out measles. Which information could help you to rule out measles? A) presence of a rash on the face, trunk, and extremities B) vaccination history and other symptoms of illness such as fever and sore throat C) other symptoms of illness such as fever and sore throat D) vaccination history E) vaccination history, other symptoms of illness such as fever and sore throat, and presence of a rash on the face, trunk, and extremities

11)

12) You are a nurse serving as a medical volunteer in a refugee camp. Due to extreme poverty, political instability, and displacement, most individuals at the camp have not received any preventative medical care, including vaccinations. While providing care to a young woman in about the fourth month of pregnancy, she mentions that several children, including her toddler, suffered from a mild illness last month. Her toddler had a low fever, a runny nose, and a rash that started on his face then moved downward. The illness resolved quickly in all the children. What illness might the children have had and why should you be concerned? A) rubella; the unborn child of the exposed mother may be stillborn or suffer from birth defects B) rubella; it is a mild, self-limiting disease so there are no further concerns C) measles; the child may develop shingles at a later time D) hand, foot, and mouth disease; the virus may re-activate at a later time E) measles; the children may be more susceptible to other infections

12)

13) A distinctive red rash on the cheeks with an otherwise mild illness is most likely A) rubella. B) chickenpox. C) fifth disease. D) measles. E) roseola.

13)

14) Which statement is not true about viral warts? A) Papillomaviruses are the cause of many warts. B) Warts result from abnormal cell growth and so are highly likely to become cancerous. C) Plantar warts are found on the feet. D) Warts can spread from one part of the body to another via autoinoculation. E) Warts can be removed but may return later.

14)

15) Which factor is not a reason Propionibacterium acnes (P. acnes) is often associated with acne? A) the ability of P. acnes to metabolize sebum B) increased oxygen levels in clogged pores favoring bacterial growth C) biofilm formation by P. acnes in pores and glands D) the inflammatory responses to P. acnes which causes pustules and cysts E) increased sebum production during adolescence

15)

16) What role do capsules and protein A play as virulence factors of Staphylococcus aureus? A) break down blood clots B) protect the bacterium from neutrophils C) protect the bacterium from phagocytosis D) lyse red blood cells E) form blood clots

16)

17) Which staphylococcal infection is not correctly matched with its description? A) Cellulitis: Deep infection of the lower dermal and subcutaneous fat B) Erysipelas: A milder form of impetigo with only localized inflammation and mild pain C) Scalded skin syndrome: Caused by the production of an exfoliative toxin D) Impetigo: Presence of pus-filled vesicles on the face, lips, or extremities, usually in children E) Folliculitis: Swollen, red, pus-filled hair follicles

17)

18) Which virulence factor of Group A streptococci (GAS) is responsible for the rapid spread of tissue death in necrotizing fasciitis? A) coagulase B) hyaluronidase C) coagulase and hyaluronidase D) hyaluronidase and streptokinase E) streptokinase

18)

19) In streptococcal toxic shock syndrome, pathology results from toxins in the bloodstream which may cause both a red skin rash, as well as A) peeling away of the epidermal layer of skin. B) formation of a blue- or green-colored pus. C) release of foul-smelling gases from the infection site. D) degradation of connective tissue. E) a decrease in blood pressure leading to organ failure.

19)

20) Cultures taken from an impetigo lesion reveal bacteria that are Gram-positive cocci which are catalase- and coagulase-negative and cause beta-hemolysis when cultured on blood agar. The responsible species is A) Streptococcus pyogenes. B) Clostridium perfringens. C) Pseudomonas aeruginosa. D) Staphylococcus aureus. E) staphylococci species other than Staphylococcus aureus.

20)

21) Which patient group is least susceptible to infections by pseudomonads? A) organ transplant recipients on immunosuppressive drugs B) otherwise healthy mothers in childbirth C) cystic fibrosis patients D) competitive swimmers who train daily E) burn patients

21)

22) Pyocyanin, a greenish-blue pigment produced by pseudomonads, acts as a virulence factor by A) forming a biofilm. B) digesting lipids in tissues. C) breaking down reactive oxygen species. D) lysing red blood cells. E) generating reactive oxygen species.

22)

23) A hospital burn unit has experienced ongoing problems with pseudomonad infections in multiple wards despite attention to patient hygiene and environmental sanitation. Which of the following would not be a possible source of the bacteria? A) hospital cafeteria B) patient room cleaning supplies C) hospital floral shop D) skin microbiota of staff E) therapy pool in the physical therapy department

23)

24) Tissue necrosis caused by Clostridium perfringens may be distinguished from necrotizing fasciitis in what way? A) emission of foul-smelling gases from the damaged tissue and presence of Gram-positive, catalase-negative cocci in the affected area B) presence of Gram-positive, endospore forming bacilli in the affected area C) emission of foul-smelling gases from the damaged tissue D) presence of Gram-positive, endospore forming bacilli in the affected area and emission of foul-smelling gases from the damaged tissue E) presence of Gram-positive, catalase-negative cocci in the affected area

24)

25) Cutaneous mycoses usually A) respond quickly to treatment with a single dose of topical antifungal medication. B) are not associated with changes in the normal microbiota. C) are invasive with a considerable risk of fatality. D) are superficial infections on the skin, hair, or nails. E) occur in the deeper dermal layers or in muscles.

25)

26) A contributing factor to cutaneous candidiasis might be A) a shift in normal microbiota and hyperactive immune function. B) dry, exposed skin. C) hyperactive immune function. D) a shift in normal microbiota. E) dry, exposed skin and hyperactive immune function.

26)

27) Which does not apply to ringworm infections? A) may occur on the feet, groin, scalp, nails, or body B) may manifest as a round skin lesion with a scaly red margin C) can be acquired by direct or indirect contact D) caused by a worm E) caused by members of the normal skin biota

27)

28) What type of infection is shown?

28)

A) impetigo B) subcutaneous mycoses C) tinea D) leishmaniasis E) candidiasis 29) Which of the following skin infections is caused by a protozoan? A) cutaneous anthrax B) dermatophytic infections C) leishmaniasis D) otitis externa E) cutaneous candidiasis

29)

30) Which statement is not true about leishmaniasis? A) It is most prevalent in the tropics and subtropics. B) It is a slow infection that can persist for months to years. C) It is transmitted by sand flies. D) It is preventable by a vaccine which is recommended for travelers to endemic areas. E) Over twenty different Leishmania species may cause leishmaniasis.

30)

31) Which protective mechanism of the eye is incorrectly matched with its description? A) Tears: Washes away microbes and contains antimicrobial chemicals B) Lacrimal gland: Produces tears C) Lysozyme: Breaks down bacterial cell walls D) Conjunctiva: Transparent layer which protects the iris E) Lactoferrin: Binds up free iron which some microbes require

31)

32) The common infection known as "pink eye" is an infection of the A) conjunctiva. B) retina. C) sclera. D) iris. E) cornea.

32)

33) A small child presents to the pediatric office with a reddened sclera, itchy eyes, and a watery, clear discharge from the affected eye. The most likely diagnosis is A) trachoma. B) viral conjunctivitis. C) bacterial conjunctivitis. D) either bacterial conjunctivitis or trachoma; further tests are needed. E) cannot be distinguished between bacterial or viral conjunctivitis so antibiotic treatment is given regardless.

33)

34) While on a medical volunteer trip to an impoverished country, you encounter a patient whose eyeli turned inward as shown. What is the cause and the best treatment?

34)

A) Acanthamoeba; corneal transplant will likely be necessary B) viral conjunctivitis; no treatment but the condition will resolve with time C) onchocerciasis (river blindness); doxycycline D) neonatal bacterial conjunctivitis; antibiotic or silver drops should have been given at birth E) trachoma; single dose of oral azithromycin 35) Several forms of keratitis are linked to A) vertical transmission during childbirth. B) improper handling of contact lenses. C) day care centers. D) re-activation of a herpes virus infection. E) hospitals or other healthcare settings.

35)

36) Onchocerciasis, or river blindness, is caused by a A) virus; fomites such as towels or bedding B) helminth; blackflies C) bacterium; gnats which swarm near the eye D) protozoan; contaminated water E) fungus; contaminated contact lens solution

and is spread via

36)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 37) The numbers and types of microbes found in the normal skin microbiota are consistent across all body surfaces.

37)

38) As measles vaccination rates have declined in recent years due to concerns about the vaccine, there have been no documented outbreaks of the disease, showing that the measles virus has been successfully eliminated from the population.

38)

39) Even though rubella is a mild, self-limiting disease, vaccination remains important to prevent severe neurological damage to babies whose mothers are exposed to rubella in utero.

39)

40) Methicillin-resistant Staphylococcus aureus (MRSA) cause the same infections as non-resistant S. aureus stains; however, the bacterium has evolved cell-wall building enzymes which do not bind with methicillin and other beta-lactam antibiotics.

40)

41) Because pseudomonads are widespread in the environment and are versatile in their metabolic capabilities, skin infections with these bacteria are common even in healthy people with no skin breaches.

41)

42) Most fungal skin infections are likely to remain superficial except in individuals who are immunocompromised.

42)

43) The eyes lack a protective normal microbiota.

43)

44) Keratitis is an inflammation of the cornea and can be caused by members of all microbial groups except viruses.

44)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 45) Describe how latency contributes to the infection process of the Varicella-Zoster and Herpes simplex-1 viruses. 46) Describe and contrast three types of bacterial skin infections that can lead to tissue necrosis and death. Name and characterize the causative bacteria, and describe epidemiological and clinical features of each disease. 47) Describe the causative agent, epidemiology, presentation, and treatment for 3 causes of infectious blindness.

Answer Key Testname: UNTITLED32

1) D 2) C 3) C 4) E 5) D 6) E 7) A 8) A 9) D 10) D 11) D 12) A 13) C 14) B 15) B 16) C 17) B 18) D 19) E 20) A 21) B 22) E 23) A 24) D 25) D 26) D 27) D 28) C 29) C 30) D 31) D 32) A 33) B 34) E 35) B 36) B 37) FALSE 38) FALSE 39) TRUE 40) TRUE 41) FALSE 42) TRUE 43) FALSE 44) FALSE

Answer Key Testname: UNTITLED32

45) The Varicella-Zoster virus causes chickenpox. After a 14-16 day incubation, the initial illness manifests as an itchy vesicular rash which may be widespread over the entire body. Fever may accompany the illness. After about a week, the vesicles scab over and slowly heal. At this point the virus enters latency in various peripheral nerves. The virus may re-emerge as a more limited outbreak of vesicles called shingles. Shingles lesions tend to be localized on the torso or face, and are often painful. Herpes simplex 1 (HSV-1) is responsible for a vesicular rash known as "cold sores" or "fever blisters", usually around the lips. After the initial illness, HSV-1 becomes latent in either the trigeminal nerve, or less commonly, the optic nerve. Re-activation of the virus may be caused by ultraviolet radiation, menstruation or other hormonal changes, or stressful conditions. HSV-1 may also manifest on other parts of the body such as herpes gladitorum or herpes whitlow. 46) Necrosis is tissue death and is usually caused by reduced blood flow to an area. Several bacterial infections can result in localized or spreading tissue necrosis. Necrotizing fasciitis is often caused by Streptococcus pyogenes, also known as Group A streptococci (GAS). S. pyogenes produces a number of virulence factors such as hyaluronidase and lipase that break down tissue and facilitate the spread of the bacteria. M protein on the surface of the bacterium serves as a binding site for plasminogen which triggers a tissue degradation cascade. Gas gangrene is caused by Clostridium perfringens, a soil bacterium which may infect deep wounds. The low-oxygen environment of deep wounds stimulates the growth of the anaerobic clostridia which produces toxins which can lead to rapid tissue death. Cutaneous anthrax is caused by Bacillus anthracis, a bacterium found in soil and often transmitted to human through contact with infected animals or their parts. The bacteria may enter skin abrasions to form a solid, blackened skin nodule. Exotoxins kill first superficial then deeper skin cells. In most cases, the damage stays localized, but prompt treatment is required. 47) Trachoma, caused by Chlamydia trachomatis is the leading cause of preventable microbial blindness. The infection causes scarring of the conjunctiva lining the eyelid, causing the eyelid to turn inward. The eyelashes then scratch the cornea, leading to permanent damage. The infection is acquired by contaminated fomite or by flies which have picked up the bacteria from the environment. The preferred treatment is a single dose of azithromycin. Various microbe can cause keratitis, a severe inflammation of the cornea. Viral keratitis is caused by reactivation of Herpes simplex-1, while bacterial and fungal keratitis is often linked to poor contact lens hygiene. Acanthamoeba, or protozoan keratitis, is caused by exposure to this organisms in natural or tap water sources. Swimming or improper contact lens hygiene is the major mode of transmission. Without early treatment, corneal transplant surgery is necessary to restore site. Onchocerciasis, or river blindness, is caused by a parasitic helminth and spread by biting blackflies. The larvae of the helminth are introduced to the skin, and may migrate to the eye. The resulting inflammation damages the optic nerve. Ivermectin and doxycycline are used for treatment.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following comprises the peripheral nervous system? A) brain B) skin C) meninges D) nerves E) spinal cord

2) The sense internal and external stimuli, and send out responses in the form of chemical messengers called . A) cerebrospinal fluids; myelins B) neurons; neurotransmitters C) meninges; axons D) dendrites; arachnoids E) muscles; chemokines

3) The term "gut-brain axis" describes the complex, back-and-forth communication that occurs between all of the following except the A) nervous system. B) endocrine system. C) muscular system. D) digestive system. E) immune system.

4) Which of the following is the layer of the meninges that has direct contact with the brain? A) dura mater B) pia mater C) arachnoid mater D) geezin mater E) dinan mater

5) Which of the following is a function of the meninges? A) supply nutrients, remove waste, and protect the CNS from physical shocks B) supply oxygen C) remove waste D) supply nutrients E) protect the CNS from physical shocks

6) Which type of molecule can diffuse through the blood-brain barrier? A) lipophilic molecules B) glucose molecules C) very small molecules and lipophilic molecules D) very small molecules E) hydrophilic molecules and glucose molecules

7) What is it called when there is only inflammation of the brain? A) endocarditis B) encephalomyelitis C) meningitis D) encephalitis E) meningoencephalitis

8) What diagnostic tool is used to confirm a diagnosis of meningitis or encephalitis? A) lumbar puncture B) throat swap C) blood count D) magnetic resonance imaging (MRI) E) computed tomography (CT scan)

9) Which of the following diseases cause flu-like symptoms in most people infected, but can cause muscle weakness or paralysis? A) spongiform encephalopathy B) tetanus C) rabies D) toxoplasmosis E) polio

10) Which of the following versions of the polio vaccine is preferred in the United States? A) transgenic DNA vaccine, which is made by inserting DNA for polio capsid proteins into the genome of a nonvirulent virus B) inactivated polio vaccine which is injected into muscle and requires several boosters C) antibiotic treatment to clear the infection D) oral polio vaccine which is made up of an attenuated viral strain E) Currently no vaccine is available, and patient isolation is the preferred method of control.

10)

11) Which of the following about the pathogenesis of rabies is false? A) the virus rapidly travels through neurons, replicating and spreading to the CNS B) the rabies virus lyses host cells which explains neurological symptoms including pharyngeal spasms, confusion, loss of coordination, delirium, and the characteristic hydrophobia C) after invading brain cells, rabies spreads back out into the PNS where it replicates and is shed from tissues that are well supplied with nerves, including the salivary glands D) a diagnostic sign of rabies is the formation of Negri bodies, small clusters of virus inside the neurons E) the virus slowly replicates in the muscle cells leading to a long incubation period that lasts from two months to a year

11)

12) Patients who suspect exposure to rabies are A) injected with antirabies antibodies. B) injected with the attenuated vaccine. C) injected with both antirabies antibodies and the attenuated vaccine. D) injected with the inactivated vaccine. E) injected with both antirabies antibodies and the inactivated vaccine.

12)

13) Which of the following is not an arbovirus? A) Lyme disease B) La Crosse C) dengue D) West Nile E) Rabies

13)

14) How do arboviruses cause nervous system infections? A) The virus invades and destroys the blood vessel cells that form the blood-brain barrier. B) The virus is capable of crossing the blood-brain barrier by binding to transport proteins in the capillaries meant to be used for various nutrients. C) The virus produces toxins that damage neuron connections. D) The virus is small enough to pass through the blood-brain barrier. E) The virus gains entry into the CNS by hijacking neurons of the PNS.

14)

15) What is the best way to protect the population against Haemophilus influenza type b infections? A) Since the chances of complications are rare, no treatment is required. B) antibiotic treatment after onset of symptoms C) use of the Hib vaccine in young children D) antitoxin treatment when exposure has occurred E) IV fluids are commonly prescribed due to loss of fluids.

15)

16) Neisseria meningitidis, which causes meningococcal meningitis, is capable of triggering sporadic disease outbreaks by which of the following methods? A) hides from the immune system inside neurons B) efficient spreading in the host by breaking down blood clots C) infecting compromised hosts D) capsular switching E) mutations due to utilization of reverse transcriptase

16)

17) What is so particular about the onset and course of meningococcal meningitis? A) Resulting diarrhea is particularly bloody if not treated within the first 24 hours. B) Bacteria are only spread through contact with sweat. C) Rash begins on patient extremities and spreads to the torso as patient itches. D) If not treated, death can occur within hours of fever onset. E) The incubation time for this type of bacteria is always 30 days.

17)

18) Group B Streptococcus is most likely to cause bacterial meningitis in which of the following age groups? A) adolescents and young adults B) infants and children C) newborns D) older adults E) It infects all age groups equally.

18)

19) Most bacterial meningitis cases in the United States are pneumococcal meningitis, caused by which of the following bacteria? A) Haemophilus influenzae B) Listeria monocytogenes C) Escherichia coli D) Streptococcus pneumoniae E) Neisseria meningitidis

19)

20) Why is the immune response to pneumococcal meningitis the most damaging aspect of the disease? A) Neurons infected with the bacteria are identified and destroyed by the immune system resulting in paralysis or in some cases death. B) A particularly potent endotoxin stimulates a rapid fever that typically holds at 104°C for 3-4 days unless other actions are taken. C) Released antibodies bind to the basal membrane of tissues which results in the damage of these tissues and the neighboring cells. D) Blood clots are formed in the circulatory system in an effort to isolate the bacteria; however, these clots are often the cause of heart attack or stroke in patients that don't seek medical treatment. E) An exotoxin stimulates severe inflammation and provokes host tissue damage as immune cells release oxygen radicals and enzyme-destroying proteins in response to the toxin.

20)

21) Which of the following is not a risk factor for contracting Listeria monocytogenes? A) immunocompromised individuals B) elderly patients C) bedridden D) neonates E) pregnant women

21)

22) How is Listeria monocytogenes capable of spreading in the body? A) Actin in the cytoskeleton propels the bacteria into an adjacent cell. B) After being phagocytized, the bacteria initiates apoptosis in the cell and spreads to other cells in the vesicles that are released from the dying cell. C) It evades the immune system by adhering to cells, being phagocytized, and then breaking out of the phagosome into the cytoplasm. D) The bacteria initiate apoptosis in the cell and spread to other cells in the vesicles that are released from the dying cell. E) The bacteria initiate apoptosis in the cell and spread to other cells in the vesicles that are released from the dying cell, and actin in the cytoskeleton propels the bacteria into an adjacent cell.

22)

23) Why is leprosy confined to the PNS? A) Cells of the CNS lack the necessary receptor for M. leprae to gain access. B) The immune system is able to hold its ground and protect the CNS. C) M. leprae are aerobic and therefore prefer having the access oxygen that living just under the tattered epidermis can provide. D) Cooler body temperatures of 30-35°C are necessary for M. leprae's growth. E) It's not, but because it grows slowly and takes decades to reach the CNS, many believe that is where it is confined.

23)

24) Which of the following is false about the lepromatous form of leprosy? A) The lepromatous form is more common than the milder tuberculoid form. B) Without treatment, lepromatous leprosy is often fatal. C) The lepromatous form can spread to others. D) The lepromatous form is more serious than the tuberculoid form. E) The lepromatous form causes irreversible tissue damage in the form of macules, papules, and nodules in many places on the body.

24)

25) Which of the following is not how botulism is contracted? A) adults eating canned vegetables such as beets, carrots, or spinach B) IV drug users who use needles contaminated with C. botulinum endospores C) Infants encounter C. botulinum endospores through wind and dust. D) Elderly farmers encounter C. botulinum endospores through wind and dust. E) Infants encounter C. botulinum endospores by eating honey.

25)

26) Botulinum toxin causes all of the following except A) flaccid paralysis. B) constipation. C) petechial rash. D) difficulty breathing. E) difficulty speaking.

26)

27) Which of the following could result in a tetanus infection? A) A fingernail of a coworker accidently scratches you. B) While squeezing through to get into your car, you get a surface abrasion from a rough and rusted panel on the car next to you. C) The nurse accidently forgets to wipe your arm with an alcohol pad before giving you your flu shot. D) A two-inch piece of wood causes a deep puncture in your arm when replacing a board on your deck. E) You order a steak when out with friends for dinner, and although it wasn't completely cooked, you ate it anyways because you didn't want to make a scene or delay anyone else from eating.

27)

28) Which of the follow is false concerning the tetanospasmin toxin? A) causes intense muscle spasms, drooling, sweating, and irritability B) leads to flaccid paralysis C) causes irreversible damage to neurons D) taken up by peripheral motor neurons and transported to the spinal cord E) blocks the release of inhibitory neurotransmitters, preventing muscle relaxation

28)

29) Which of the following paths does Cryptococcus neoformans take to get to the CNS?

29)

A) lungs → macrophages → lymphatic system → blood → CNS B) muscles → blood → CNS C) stomach → intestines → blood → CNS D) skin → blood → CNS E) nose → CNS

30) Which of the following is false about the tropical disease African sleeping sickness? A) It is carried by a blood-sucking mosquito from host to host. B) If the disease goes untreated, it is fatal. C) It is caused by the flagellated protozoan Trypanosoma brucei. D) Those infected cannot sleep at night and cannot stay awake during the day. E) It induces an immune system reaction so strong that host neutrophils can harm host neurons.

30)

31) Primary amoebic meningoencephalitis is caused by A) Naegleria fowleri. B) Trypanosoma brucei. C) Listeria meningitis. D) Toxoplasma gondii. E) Cryptococcus neoformans.

31)

32) Which of the following about Naegleria fowleri is true? A) Although debilitating, most patients live long lives. B) The organism prefers warm stagnant waters. C) Infection occurs when contaminated water is ingested. D) This bacteria typically feeds off of nutrients in the soil. E) Only the flagellated form of the protozoan is infectious.

32)

33) Which of the following is false about toxoplasmosis? A) Tachyzoites can invade tissues like the heart, muscles, eyes, and brain. B) Cats act as the definitive host, shedding the protozoans in their feces. C) It is caused by a protozoan called Toxoplasma gondii. D) Meningitis results in a majority of patients since there are currently no treatment options. E) Risk factors include eating raw or undercooked meat such as wild game, pork, and shellfish.

33)

34) Congenital toxoplasmosis can cause all of the following except A) deafness. B) convulsions. C) neurological disabilities. D) anemia. E) miscarriage or stillbirth.

34)

35) Which of the following is true about spongiform encephalopathies? A) The disease is tied to a normal cellular prion protein (PrPC) that is found mostly on the surface of neurons. B) When the normal prion protein encounters an abnormally shaped version of itself, PrPSC, the

35)

normal prion's shape is changed and it becomes an infectious PrPSC. C) Spongiform encephalopathies occur in a wide variety of mammals, but the infectious prions are species specific and do not cause disease in other species. D) Abnormal prions clump together and kill the affected neurons, which accounts for the spongelike appearance of brain tissue found in TSE autopsies. E) Spontaneous cases of Creuztfeldt-Jakob disease may be caused by mutations during cell division in neuronal stem cells. TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) A lumbar puncture allows for CSF analysis to differentiate between viral and bacterial meningitis.

36)

37) Encephalitis is most often caused by a virus.

37)

38) Rabies is the only virus that infects the PNS.

38)

39) The West Nile virus damages neurons by lysing them as they exit after replication or by triggering apoptosis.

39)

40) The tetanospasmin toxin blocks normal inhibition while botulinum toxin blocks normal stimulation.

40)

41) C. gattii is usually contracted from urban environments, C. neoformans is associated with natural settings.

41)

42) Protists reproduce through sexual as well as asexual means, depending on their life stage.

42)

43) When infected with Toxoplasma gondii, a protist, symptoms are always present within two weeks.

43)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 44) A new drug for depression was developed by taking a disaccharide, sucrose, and combining several different hydrophilic functional groups onto the molecule. After hearing about its structure, you are positive that this molecule has zero direct effect on the brain. Why? 45) Why has polio been eradicated in the U.S. but is still present in developing nations, including Afghanistan and Pakistan? 46) Explain why children under 1 year old should not be fed honey, yet honey is okay to eat for older healthy individuals.

Answer Key Testname: UNTITLED33

1) D 2) B 3) C 4) B 5) A 6) C 7) D 8) A 9) E 10) B 11) B 12) E 13) E 14) A 15) C 16) D 17) D 18) C 19) D 20) E 21) C 22) A 23) D 24) A 25) D 26) C 27) D 28) B 29) A 30) A 31) A 32) B 33) D 34) D 35) C 36) TRUE 37) TRUE 38) FALSE 39) TRUE 40) TRUE 41) FALSE 42) TRUE 43) FALSE 44) The blood brain barrier is going keep this drug from coming in contact with the brain because this new drug is too large and is hydrophilic instead of lipophilic. If this drug is significantly stopping depression then it is utilizing an indirect pathway that should be studied more.

Answer Key Testname: UNTITLED33

45) Although developed nations have been able to acquire and distribute vaccines against polio, certain war -torn developing nations do not have the resources to focus on vaccine initiatives. Religious or cultural practices may also influence acceptance of vaccination, as they sometimes do in the United States. However, this is a world-wide problem because as long as one person is left infected, it could quickly spread all over the world if vaccination efforts are stopped too soon. 46) Honey can often contain C. botulinum endospores. The gastric acids in the digestive tract trigger endospore germination, allowing a temporary production of the toxins as the C. botulinum travels through the GI tract. A survey of U.S. honey products showed that from 2 to 24 percent of them contained C. botulinum endospores. In older children and adults, a mature immune system and the healthy microbes that live in the gastrointestinal tract usually prevent C. botulinum from finding a place to grow. But infants are not fully colonized by helpful bacteria, and their immune system is still maturing so C. botulinum encounters little competition, and will readily grow and produce its toxins.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) What is the correct order of the following eight parts of the GI tract?

A) mouth, pharynx, esophagus, stomach, large intestine, small intestine, rectum, anus B) mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus C) mouth, esophagus, pharynx, stomach, large intestine, small intestine, rectum, anus D) mouth, esophagus, stomach, pharynx, small intestine, large intestine, rectum, anus E) mouth, esophagus, pharynx, stomach, small intestine, large intestine, rectum, anus

2) Why is lymphatic tissue found all along the GI tract? A) Upon infection in a specific area of the GI tract, a response can quickly be delivered and flood the lumen of the GI tract in that region. B) Cells in these lymphatic tissues "sample" the environment by phagocytosis and present their findings to lymphocytes that may or may not need to initiate an immune response. C) Different pathogens are activated at different points along the digestive tract, and the location of the lymphatic tissue allows the host to respond according to which pathogen is activating in that area. D) When an infection occurs, these lymphatic tissues are able to quickly trigger an inflammatory response along the entire GI tract. E) When an infection occurs, these lymphatic tissues are able to quickly stop digestion and the movement of the GI contents so that the infection doesn't spread throughout the body.

3) The in inhibit the growth of many bacteria. A) acidity; stomach mucus B) fats; saliva C) toxins; chyme D) lysozymes; gastric juice E) salts; bile

4) Stool is rich in which of the following organisms? A) Fusobacterium B) Bacteriodes C) Neisseria D) Streptococcus E) Actinomyces

5) An important source of vitamin K in the intestine comes from which species? A) Vibrio cholerae B) Escherichia coli C) Helicobacter pylori D) Giardia lamblia E) Streptococcus mutans

6) Dysentery can lead to A) gastroenteritis B) enteritis C) gastritis D) diarrhea E) hypovolemic shock

and/or organ failure if medical attention is not sought in time.

7) Which of the following is able to identify the pathogen responsible for intestinal symptoms? A) microscopic examination of stool samples B) selective and differential culture media, molecular techniques, and microscopic examination of stool samples C) upper GI endoscopy and colonoscopy D) molecular techniques E) selective and differential culture media

8) Which of the following does the mumps virus infect? A) parotid glands B) pancreas C) stomach D) reproductive organs E) lacrimal glands

9) Although four of the following options describe both rotavirus and norovirus, which one specifically describes norovirus? A) definitive diagnosis requires detecting the RNA virus in the patient stool sample B) symptoms include vomiting, diarrhea, and nausea C) RNA virus D) common in long-term care facilities E) spreads via the fecal-oral route

10) Which hepatitis virus has a genome made up of double-stranded DNA? A) hepatitis A B) hepatitis B C) hepatitis C D) hepatitis D E) hepatitis E

10)

11) Which hepatitis virus requires an additional hepatitis infection in order to be virulent? A) hepatitis A B) hepatitis B C) hepatitis C D) hepatitis D E) hepatitis E

11)

12) Which two hepatitis viruses primarily use the fecal-oral route for infection? A) hepatitis B and hepatitis C B) hepatitis B and hepatitis D C) hepatitis A and hepatitis E D) hepatitis C and hepatitis D E) hepatitis D and hepatitis E

12)

13) What do chronic hepatitis infections result in? A) constipation B) cirrhosis, liver failure, or hepatocellular carcinoma C) heart failure D) constipation, ulcers, or colon cancer E) kidney failure or kidney cancer

13)

14) Which hepatitis virus only results in acute infections? A) hepatitis A B) hepatitis B C) hepatitis C D) hepatitis D E) hepatitis E

14)

15)

is characterized by tender, swollen gums with a bright red or purplish coloration; the gums may also pull away from teeth, and bad breath and tooth loss are also frequent manifestations. A) Periodontal disease B) Thrush C) Gingivitis D) Dental caries E) Oral yeast infection

16) Bacteria metabolize sugars and they create dental caries. A) toxins; dentin B) proteins; pulp C) acids; enamel D) spores; gums E) chemicals; pulp

that can eat away at the

to cause

15)

16)

17) Which of the following is not true about the interaction of biofilms on teeth? A) When plaque calcifies into tartar it must be scraped off the teeth. B) Limiting dietary fats reduces lactic acid production by the bacteria in dental plaque and decreases the risk for dental caries, C) Brushing teeth twice daily and flossing will physically remove superficial plaque layers. D) Bacterial growth within deeper biofilm layers and new bacteria entering the mouth quickly reestablish what was removed from brushing. E) Dentists recommend a twice-yearly dental cleaning and checkup to limit caries and periodontal disease,

17)

18) How does Helicobacter pylori cause stomach ulcers? A) Polar flagella help bacteria burrow into mucosal lining to escape stomach acid, where enzymes decrease the acidity around them, and they release a toxin to kill host cells. B) Bacterial capsules allow the bacteria to survive in the acidic lumen of the stomach as it releases toxins that bind to and destroy the epithelial lining of the stomach. C) Peritrichous flagella help the bacteria squeeze through the mucosal lining to avoid stomach acid, where cytokine imposters are released which attract B cells and cause the immune response to destroy the epithelial lining of the stomach. D) The glycocalyx protects the bacteria from stomach acid as the bacteria enters a susceptible host and binds to an area of epithelial cells in the stomach with thin mucosa where toxins cause further damage and allow entry. E) Fimbriae enable to bacteria to penetrate the mucosa and bind to the epithelial lining of the stomach where toxins are released that bind and destroy epithelial cells.

18)

19) Which of the following describes a case of food poisoning? A) Toxins from Staphylococcus aureus, Bacillus cereus, and Clostridium perfringens are responsible. B) After ingestion, a pathogen establishes infection in the host. C) Symptoms begin 1-5 days after exposure. D) Recovery time can take anywhere from days to weeks. E) Signs and symptoms include fever, headache, muscle aches, nausea, diarrhea, and abdominal pain.

19)

20) Which of the following is false of Campylobacter jejuni infections? A) Infections are primarily associated with eating undercooked beef or cross-contaminating foods with raw beef juices. B) Although symptoms usually resolve within a week, in immune-compromised patients the bacteria may cause bacteremia, which could lead to sepsis and possibly septic shock. C) Antibodies that recognize C. jejuni's lipopolysaccharides can cross-react with sugars on neurons that trigger an autoimmune response against the nervous system called Guillain-Barré syndrome. D) It is a Gram-negative, flagellated, spiral-shaped bacterium that grows best in microaerophilic conditions. E) After ingestion, the bacteria burrow through the mucosal layer of the intestine and migrate through intestinal epithelial cells to multiply just beneath the epithelial layer.

20)

21) Eating peanut butter, cantaloupe, chicken products, seafood, spinach, or handling a pet turtle are all sources of infection for which of the following bacteria? A) Salmonella enterica serotype Typhi B) Salmonella enterica serotype Enteritidis C) Shigella dysenteriae D) Campylobacter jejuni E) Esherichia coli O157:H7

21)

22) Which of the following bacteria can thrive even if frozen? A) Listeria monocytogenes B) Salmonella enterica C) Shigella dysenteriae D) Esherichia coli E) Campylobacter jejuni

22)

23) Which of the following is false of Shigella infections? A) It can induce hemolytic uremic syndrome with symptoms that include hematuria, purpura, and edema. B) The Shiga toxin targets ribosomes to block protein synthesis and kill host cells. C) The elderly are most likely to become infected. D) It spreads from person to person and also through human fecal contamination of food, water, or environmental surfaces that are touched. E) In the United States, S. sonnei accounts for about 75 percent of Shigella cases, while S. flexneri predominates in developing countries.

23)

24) Which of the following is not a virulence factor of Shigella species? A) the ability to escape from phagocytes B) the capacity to pass between infected cells using an actin propulsion system C) the manufacture of several toxins that damage intestinal cells and induce fluid efflux D) the capability to cause stomach ulcers E) a system that induces host cells to endocytose the bacteria

24)

25) Why should antibiotics not be given to a patient with Escherichia coli O157:H7? A) Antibiotics do not reduce disease and may precipitate HUS. B) Antibiotics tend to act as a hapten with this infection and are likely to cause an allergic response. C) This pathotype is only found in cattle and does not infect humans. D) This is not a bacterium, and therefore antibiotics would be ineffective. E) This pathotype is part of the normal digestive tract of humans.

25)

26) Which of the following would not result from a cholera infection? A) mild to profuse diarrhea B) organ failure and death C) pseudomembranous colitis D) hypovolemic shock E) leg cramps

26)

27) Which of the following would not result from a C. difficile infection? A) hemolytic uremic syndrome B) pseudomembranous colitis C) mild diarrhea D) toxic megacolon E) severe abdominal pain, fever, nausea, and abundant watery diarrhea that may progress to dysentery

27)

28) Which of the following is not a reason why Clostridium difficile is an increasing concern in healthcare settings? A) antibiotic resistance B) emerging superstrains that make a third type of toxin C) the bacterium can naturally escape drugs and disinfectants by retreating into a resistant spore state D) additional modes of transmission have occurred in several isolated cases E) antibiotic misuse and overuse in the population

28)

29) A major difference between protozoans and helminths is that protozoans are A) parasitic. B) multicellular. C) able to survive outside of a host. D) archaea. E) unicellular.

29)

30) Besides diagnosing giardiasis via microscopic evaluation of feces for cysts or trophozoites, it can also be diagnosed A) by a blood sample. B) by a urine sample. C) using PCR. D) by detecting Giardia antigens. E) by a spinal fluid sample.

30)

31) Which of the following features have not helped Giardia become the most common intestinal parasite? A) It can be transmitted via fecal-oral route, via contaminated fomites, or from direct contact with an infected patient. B) No drugs are currently available for treatment. C) A tough cyst form that resists chlorine disinfection used for municipal water treatment, UV light, and freezing. D) It lives in animals other than humans. E) Ingesting as few as 10 cysts is sufficient to establish infection.

31)

32) Even though 90 percent of infections are asymptomatic, why should you always treat amebiasis? A) Asymptomatic patients can continue to spread the disease for years before dying themselves. B) Pseudomembranous plaques form along the colon lining as toxins cause tissue damage in 10 percent of hosts. C) The immune system of the host can quickly become compromised. D) Exotoxin production can promote a vigorous inflammatory response in certain patients and also damage the cytoskeleton of the colon's epithelial cells. E) The protozoan can cause invasive disease that affects the liver, lungs, and brain.

32)

33) How are Cryptosporidium sporozoites able to evade the immune system? A) They escape from phagocytes. B) They evade phagocytosis by using a capsule. C) Special proteins bind and inhibit antibodies from adhering to them. D) They attach to host cells and build a protective membrane from modified host cell membrane materials. E) They reside inside the host cells.

33)

34) Which of the following describe the typical lifecycle of amebiasis? A) host makes contact with contaminated object; swallows cysts; trophozoites released from cysts; trophozoites reproduce in digestive tract; trophozoites travel to the lungs, trophozoites form cysts, cysts are coughed up and released from host in relatively large respiratory droplets that people sneeze, cough, drip, or exhale B) host is bitten; cysts enter the bloodstream; trophozoites released from cysts in blood; trophozoites travel to and reproduce in the liver; new trophozoites circulate in blood, trophozoites are eaten by a new insect where they then form cysts C) host makes contact with contaminated object; swallows cysts; trophozoites released from cysts; trophozoites reproduce in digestive tract; trophozoites travel to the lungs, trophozoites form cysts, cysts are coughed up, swallowed, and released from host in feces D) host makes contact with contaminated object; swallows cysts; trophozoites released from cysts in digestive tract; trophozoites travel to and reproduce in the liver; trophozoites travel to the lungs, trophozoites form cysts, cysts are coughed up, swallowed, and released from host in feces E) host makes contact with contaminated object; swallows cysts; trophozoites released from cysts; trophozoites reproduce in digestive tract; trophozoites and new cysts are released from host in feces

34)

35) Which of the following uses cows as the intermediate host? A) Taenia asiatica B) Taenia solium C) Taenia saginata D) Necator americanu E) Enterobius vermicularis

35)

36) Cysticercosis is a result of infection with which species? A) Taenia solium B) Necator americanu C) Taenia asiatica D) Enterobius vermicularis E) Ascaris lumbricoides

36)

37) How does a patient typically become infected with hookworms? A) The worm penetrates the skin when the patient walks outside barefoot. B) Cysts are ingested when the patient eats undercooked meat. C) Cysts are spread onto fomites when an infected host does not properly wash their hands and then the patient touches that object and doesn't wash their hands before eating. D) Cysts are spread via respiratory droplets when an infected host coughs or sneezes. E) Eggs are ingested when the patient eats infected seafood.

37)

38) Which hosts does the tapeworm Diphyllobothrium latum require to complete its lifecycle? A) pigs and mammals B) ants, sheep, and mammals C) cows and humans D) crustaceans, fish, and mammals E) snails, chickens, and mammals

38)

39) How do you test for a pinworm infection? A) PCR B) microscopic identification of eggs in stool C) screening for molecular antigens D) microscopic evaluation of stool for oocyst E) tape adhesion test

39)

40) Which of the following helminths is known for moving out of the body through the anus, nose, or mouth? A) Ascaris lumbricoides B) Enterobius vermicularis C) Schistosoma haematobium D) Necator americanu E) Trichinella spiralis

40)

41) Trichinellosis, also known as trichinosis, occurs when A) ingested cysts mature into adult worms and cause the host to suffer from malnutrition. B) ingested cysts mature into adult tapeworms and release proglottids that force their way out of the anus. C) ingested cysts mature into adult roundworms and release thousands of eggs as the adult releases toxins to promote severe diarrhea. D) inhaled cysts perforate the lungs as they make their way to the intestines. E) ingested cysts mature into worms in the intestines and the larvae migrate into blood and embed in muscles.

41)

42) What causes schistosomiasis? A) roundworm B) blood fluke C) pinworm D) hookworm E) tapeworm

42)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 43) Tonsils at the back of the throat, the appendix, and Peyer's patches of the small intestine are all examples of mucosa-associated lymphoid tissue (MALT) found along the GI tract.

43)

44) An important source of vitamin B in the intestine comes from Escherichia coli.

44)

45) Upper GI and lower endoscopy are tools that can be used to identify the precise microbe responsible for GI symptoms.

45)

46) Besides mumps causing swelling of the parotid salivary glands, it can also cause meningitis and orchitis.

46)

47) After infection with a norovirus, the patient will be immune from all future norovirus infections.

47)

48) Limiting dietary sugars reduces lactic acid production by the bacteria in dental plaque and decreases the risk for dental caries.

48)

49) Oral rehydration is usually sufficient for most patients to fully recover from Vibrio cholerae.

49)

50) Giardiasis and cryptosporidiosis are both caused by helminth infections.

50)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 51) In what ways are we finding that the gut microbiota affects our health? 52) What are the differences between a foodborne infection and food poisoning? 53) In what ways do helminths overcome the challenges of maintaining such complicated lifecycles?

Answer Key Testname: UNTITLED34

1) B 2) B 3) E 4) B 5) B 6) E 7) B 8) A 9) D 10) B 11) D 12) C 13) B 14) A 15) A 16) C 17) B 18) A 19) A 20) A 21) B 22) A 23) C 24) D 25) A 26) C 27) A 28) D 29) E 30) D 31) C 32) E 33) D 34) E 35) C 36) A 37) A 38) D 39) E 40) A 41) E 42) B 43) TRUE 44) FALSE 45) FALSE 46) TRUE 47) FALSE 48) TRUE 49) TRUE 50) FALSE 10

Answer Key Testname: UNTITLED34

51) In addition to making vitamins and competing with pathogens, our GI microbiota may impact metabolism and obesity; affect the development of depression and diseases such as diabetes; and train and modulate immune responses. 52) Food poisoning is not due to a living pathogen but rather an ingested toxin which produces symptoms within 6 hours of exposure, much faster than a bacteria could due to needing to grow and reproduce. Symptoms of food poisoning are usually nausea and vomiting, and sometimes diarrhea and abdominal pain whereas an infection produces fever, headache, muscle aches, nausea, diarrhea, and or abdominal pain. Recovery is usually within 24 hours but can take several days in severe cases, where as a foodborne infection takes days to weeks for the body to remove the bacteria. 53) Helminths overcome the challenges of requiring multiple hosts to complete their lifecycle by (1) producing extremely large numbers of eggs, cysts, oocysts, or larvae for an extended amount of time. By not directly or quickly killing the host, the adults can (2) produce offspring for years in some cases. By (3) triggering diarrhea or anal itching, the offspring are more likely to contaminate objects or hands and have an easier time spreading to a new host. This urgency also increases the chances of the host not making it to deposit the stool in an approved location which again increases the chances for others to become contaminated. Some helminths are not confined to living inside a host and instead (4) spend part of their lifecycle as a free living entity until it can locate an adequate host for the next phase of its life cycle.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Infection in the urinary tract is limited by all the following except A) the flushing action of urine through the ureters and urethra. B) the slightly acidic pH of urine. C) constriction of the urethra by the prostate gland in men. D) constriction of the urethra by the prostate gland in men and the placement of the urethra near the anus in women. E) the urinary microbiome.

2) Anatomical factors that cause women to be at higher risk of urinary tract infections than men include A) more acidic urine in women. B) the flushing of the urethra during ejaculation in men. C) antimicrobial peptides found in the seminal fluid in men. D) a shorter urethra positioned closer to the anus in women. E) separate openings for the urinary and reproductive tracts in women.

3) Which statement is not true about the urinary microbiome? A) Shifts in microbiome composition may be associated with physiological concerns such as incontinence. B) The species composition is consistent throughout the urinary system, across the lifespan or from person to person. C) The most consistently detected species are Lactobacillus and Streptococcus. D) The healthy urinary tract was believed to be sterile until molecular methods of analysis became available. E) Most species can be cultivated using standard laboratory techniques.

4) The placenta A) consists only of maternal tissue. B) allows diffusion of nutrients, gases, and wasted between the mother and the fetus. C) allows mixing of maternal and fetal blood. D) consists only of fetal tissue. E) is a site in which bacteria have never been detected.

5) Which is not an innate protection of the female reproductive tract? A) Normal microbiome members generate products which prevent pathogen growth. B) The vaginal lining sheds its cells every few hours. C) Lysozyme and antimicrobial peptides are present in vaginal secretions. D) Mucous secretions trap microbes. E) The vaginal lining contains ciliate cells which trap and expel bacteria from the tract.

6) TORCH pathogens are all characterized by A) transmission through sexual contact and the ability to cause intrauterine infections. B) the ability to cause intrauterine infections which are linked to infertility. C) the ability to cross the placenta to infect a developing fetus. D) transmission through sexual contact. E) transmission through sexual contact, the ability to cause intrauterine infections which are linked to infertility, and the ability to cross the placenta to infect a developing fetus.

7) The dominant genus in the vaginal microbiome of reproductive-age women, Lactobacillus, acts to limit infection by A) producing bacteriocins, a group of antimicrobial peptides. B) producing lactic acid, hydrogen peroxide, and bacteriocins. C) producing lactic acid and hydrogen peroxide. D) producing hydrogen peroxide, which is toxic to anaerobic pathogens. E) producing lactic acid by fermenting glycogen secretions, lowering pH.

8) Compared to complicated urinary tract infections (UTIs), uncomplicated UTIs are less likely to A) involve a bacterial infection. B) be diagnosed in women rather than men. C) respond to antibiotic therapy. D) recur after initial treatment. E) be diagnosed in otherwise healthy individuals.

9) Of the following, which is the most serious condition? A) pyelonephritis B) cystitis C) ureteritis D) urethritis E) urethritis and cystitis

10) A urine dipstick test can diagnose urinary tract infections by indicating A) elevated levels of leukocyte esterase. B) elevated creatine and BUN levels. C) direct detection of Gram-positive or Gram-negative bacteria. D) the presence of glucose in the urine. E) conversion of nitrite to nitrate in the urine.

10)

11) Bacterial infections that reach the kidneys can result in which serious complication? A) bacteremia and impaired renal function B) malignancies of the kidney C) impaired renal function due to scar tissue D) bacteremia, impaired renal function, and malignancies E) bacteremia as bacteria use the renal blood vessels to enter wider circulation

11)

12) Urinary catheters pose risks of causing urinary tract infections because A) they provide a surface for bacterial biofilms to establish. B) they block urine flow out of the bladder and they can introduce bacteria from the skin, anal, or external genital areas into the bladder. C) they block urine flow out of the bladder. D) they can introduce bacteria from the skin, anal, or external genital areas into the bladder. E) they provide a surface for bacterial biofilms to establish and they can introduce bacteria from the skin, anal, or external genital areas into the bladder.

12)

13) Uropathogenic E. coli can use all the following virulence factors to establish infection in the urinary tract except A) siderophores. B) invade bladder cells to become intracellular. C) pili and adhesions. D) proteases and toxins. E) antigen mimicry.

13)

14) The demographic group most likely to experience a urinary tract infection caused by Staphylococcus saprophyticus is A) sexually active young men. B) sexually active young women. C) elderly individuals of both sexes. D) pregnant women. E) elderly men with an enlarged prostate gland.

14)

15) A young woman presents to the emergency room with fever, headache, and vomiting. Food poisoning is suspected, she is given supportive care, and released. One week later she returns to the hospital in acute renal failure. A medical history reveals that she had been a volunteer at an orphanage in a rural section of a Caribbean island recently hit by a hurricane. During evacuation from the island, she had to wade through floodwaters suffered several abrasions on her legs and feet. What is the most likely pathogen based on her symptoms and history? A) BK virus B) leptospirosis C) candiduria D) Staphylococcus saprophyticus E) uropathogenic E. coli

15)

16) A man presents to the physician's office complaining of irritation in the genital area. Examination reveals a bright red rash with raised pustules with clear fluid. Upon questioning, the man reports he has recently been sexually active. What is the most likely diagnosis based upon the appearance of the genital lesions? A) genital warts caused by HPV B) syphilis C) chlamydia D) genital herpes caused by HSV-2 E) gonorrhea

16)

17) As with all human herpes virus infections, an important characteristic of HSV-2 infection is A) complete immunity once the infection has been successfully eradicated by the body. B) an ongoing a latent infection in peripheral nerves which can reactivate periodically. C) resistance to all anti-viral medications. D) that it is highly dangerous even to immune-competent adults. E) progressively worsening outbreaks each time the virus comes out of latency.

17)

18) The more dangerous CNS and disseminated forms can be minimized through which of the following interventions? A) administration of antiviral drugs to the affected newborn and delivery by cesarean section B) vaccination of pregnant women C) delivery by cesarean section and vaccination of pregnant women D) administration of antiviral drugs to the affected newborn E) delivery by cesarean section

18)

19) Characteristics of the human papilloma virus include all except A) ubiquitous virtually all sexually active individuals will become infected at some point. B) promote cell division in epithelial cells. C) easily spread through any kind of sexual contact. D) have a high mutation rate, meaning vaccine development is challenging. E) multiple strains, most of which cause asymptomatic infections.

19)

20) The advantages of the Pap smear as a means of cancer detection include A) it can detect reproductive tract cancers in both women and men. B) it is inexpensive and easy to perform, and it can detect early-stage cancers and precancerous changes. C) it is inexpensive and easy to perform, and it can detect reproductive tract cancers in both women and men. D) it can detect early-stage cancers and precancerous changes. E) it is inexpensive and easy to perform.

20)

21) Which is the true statement about vaginosis and vaginitis? A) Vaginitis describes vaginal inflammation while vaginosis does not. B) Vaginitis is always due to microbiome dysbiosis. C) The two conditions are always mutually exclusive. D) Vaginosis is not likely to be sexually transmitted. E) The two conditions are always seen together.

21)

22) Which of the following is not one of the signs assessed using Amsel's criteria to diagnose bacterial vaginosis? A) clue cells attached to vaginal epithelial visible upon microscopic examination B) greyish-white vaginal discharge C) fishy odor after addition of potassium hydroxide to a vaginal smear D) vaginal pH greater than 4.5 E) presence of any type of redness or rash

22)

23) Chlamydia may result in any of the following except A) urethritis in males. B) severe neurological disorders such as seizures, vertigo, memory and sensory impairment, and paralysis. C) neonatal conjunctivitis. D) pelvic pain with fever in women. E) pelvic inflammatory disease in women.

23)

24) Which numbered stage(s) of the Chlamydia trachomatis life cycle pictured involves the dormant elementary body?

24)

A) 5

B) 2

C) 2 & 3

D) 1 & 5

E) 1

25) Lymphogranuloma venereum differs from the infection caused by the trachoma biovar of Chlamydia trachomatis in that A) lymphogranuloma venereum is not sexually transmitted. B) lymphogranuloma venereum is not treatable with antibiotics such as doxycycline. C) lymphogranuloma venereum may result in the formation of buboes and tissues necrosis. D) lymphogranuloma venereum bacteria do not have an intracellular lifestyle. E) lymphogranuloma venereum is not treatable with antibiotics such as doxycycline and is not sexually transmitted.

25)

26) A 48-hour old infant is brought to the clinic with signs of severe bacterial conjunctivitis (infection of the eye). The infant was born at home, with the birth assisted only by an unlicensed midwife, and no pharmaceutical interventions performed on the mother or infant. Which infectious agents is the likely culprit? A) bacterial vaginosis due to mixed anaerobic species B) HSV-2 C) Chlamydia trachomatis D) Neisseria gonorrhoeae E) Neither Chlamydia trachomatis nor Neisseria gonorrhoeae should be ruled out without further testing.

26)

27) Chlamydia and gonorrhea often present a similar clinical picture except that A) chlamydia is more likely to be asymptomatic in women while gonorrhea is more likely to be asymptomatic in men. B) few strains of chlamydia are antibiotic-resistant while gonorrhea shows extensive antibiotic resistance. C) only chlamydia can be passed to and affect a newborn. D) gonorrhea infection confers strong long-term immunity while chlamydia does not. E) only gonorrhea is implicated in pelvic inflammatory disease.

27)

28) Pelvic inflammatory disease is characterized by all the following except A) increased risk for ectopic pregnancy. B) can be caused by several types of bacterial pathogens. C) treatment with antibiotic therapy. D) inflammation, swelling, or abscesses in the internal reproductive organs. E) a clear set of signs and symptoms that make diagnosis straightforward.

28)

29) Ulcerative lesions are characteristic of which stage of syphilis? A) primary stage B) secondary stage C) tertiary stage D) secondary and tertiary stages E) primary and tertiary stages

29)

30) Characteristics of Treponema pallidum, the bacterium which causes syphilis, include all except A) ability to avoid immune detection by varying the few antigens it carries on its surface. B) not treatable with any of type antibiotic. C) Gram-negative spirochete. D) rapid invasion of host tissues from the initial infection site. E) vertical transmission to a fetus during any stage of pregnancy.

30)

31) Unlike many other STIs, chanchroid is often symptomatic with treatment as patients actively seek medical attention. A) disseminated body-wide rash B) high fever C) painful lesions, disseminated body-wide rash, and high fever D) painful lesions E) painful lesions and disseminated body-wide rash

31)

resulting in quick

32) Which of the following would be observed as a result of vulvovaginal candidiasis? A) a "cottage cheese" discharge B) pus-filled lesions and a "cottage cheese" discharge C) clue cells D) pus-filled lesions E) clue cells and a "cottage cheese" discharge

32)

33) Why is hyphal morphology (as opposed to a unicellular morphology) necessary for symptomatic vaginal candidiasis to develop? A) The hyphal form is easily sexually-transmitted. B) The hyphal form displaces the normal bacterial residents of the vagina. C) The hyphal form is resistant to anti-fungal drugs. D) The hyphal form causes hormonal changes in the patient which promotes dysbiosis. E) The hyphal form produces proteases that cause cellular damage which results in inflammation.

33)

34) Trichomoniasis is characterized by A) structural morphogenesis linked to pathology. B) non-motile pathogen that forms persistent biofilms. C) dysbiosis of the microbiome. D) many asymptomatic infections. E) the need for long-term antibiotic therapy to result in a cure.

34)

35) A 30-year-old woman who is not pregnant presents with a foul-smelling, greenish vaginal discharge, indicating some form of vaginitis. A smear is taken, and routine tests performed. A motile, unicellular eukaryote with multiple flagella and an undulating membrane is observed in the microscope. What treatment is recommended? A) topical antifungal cream B) combination therapy of ceftriaxone and azithromycin C) doxycycline D) single dose of metronidazole E) clindamycin

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) No bacteria have been detected in the semen of healthy men.

36)

37) A urine dipstick test is negative for elevated nitrite, but bacteriological culturing reveals Gram-positive cocci. Uropathogenic Escherichia coli is indicated.

37)

38) Although HSV-1 usually causes oral lesions and HSV-2 usually causes genital lesions, it is possible that oral sexual contact can transmit HSV-1 to the genitals and HSV-2 to the mouth.

38)

39) The majority of human papilloma virus strains are oncogenic, and most infections lead to cancer.

39)

40) Despite the approval of several vaccines against human papilloma virus since 2006, infection rates of HPV in young women have not declined.

40)

41) Vaginosis may be experienced without accompanying vaginitis, but vaginitis always accompanies vaginosis.

41)

42) A vaginal swab examined under the microscope reveals the presence of clue cells. Bacterial vaginosis is likely indicated.

42)

43) Men, rather than women, make up the majority of syphilis cases.

43)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 44) Describe the features that limit infection in the male and female urogenital systems. 45) Describe how to diagnose a lower urinary tract infection (UTI) and differentiate between common bacterial causes. 46) Describe two pathologies that can result from a dysbiosis of the vaginal microbiome and describe how you could differentiae them. What factors can lead to dysbiosis?

Answer Key Testname: UNTITLED35

1) D 2) D 3) E 4) B 5) E 6) C 7) B 8) D 9) A 10) A 11) A 12) E 13) E 14) B 15) B 16) D 17) B 18) A 19) D 20) B 21) A 22) E 23) B 24) D 25) C 26) E 27) B 28) E 29) E 30) B 31) D 32) A 33) E 34) D 35) D 36) FALSE 37) FALSE 38) TRUE 39) FALSE 40) FALSE 41) FALSE 42) TRUE 43) TRUE

Answer Key Testname: UNTITLED35

44) In both men and women, factors that limit infection in the urinary tract include the slightly acidic pH and the flushing action of the urine through the ureters and urethra. In women, the much shorter urethra and the proximity of the urethral opening to anus make women more likely than men to experience urinary tract infections (UTIs). The microbiome of the urinary tract may provide protection against infection, but the relationship is not well-understood at this time. In females, the vagina has a number of protective features. Vaginal epithelial cells shed continually, taking potential pathogens with them. Vaginal and cervical mucous traps microbes and contains antimicrobial peptides and lysozyme. The vaginal epithelium releases glycogen which nourishes the main member of the vaginal microbiome, the lactobacilli. Fermentation of the glycogen to lactic acid lowers the vaginal pH significantly. The lactobacilli also produce hydrogen peroxide and bacteriocins which are toxic to anaerobic bacteria. 45) Signs and symptoms of a lower UTI include frequent, urgent, and/or painful urination. Pyuria or hematuria may be observed. Urine may be cloudy or smell foul. The patient may experience lower abdominal pain. A urine dipstick test may be used to check for additional indicators of a UTI such as elevated white blood cells and the presence of nitrite (indicative of bacteria reducing nitrate found in urine). Urine samples can be cultured to detect bacterial growth. Uropathogenic Escherichia coli (UPEC) the most frequent cause of uncomplicated UTIs. UPEC are small, flagellated, Gram-negative rods with a variety of virulence factors including pili, adhesins, siderophores, toxins, and avoidance of immune cells by invading epithelial cells of the bladder. The most common Gram-positive cause of bacterial UTIs is Staphylococcus saprophyticus, primarily affecting young, sexually active women. This bacterium is found on the external genitalia of both males and females. It is not able to reduce nitrate to nitrite, a common marker of infection detected by the urine dipstick test. 46) Bacterial vaginosis is a polymicrobial condition that is best defined as an absence of Lactobacillus in the vaginal microbiota. The reduction of lactobacilli is accompanied by an increase in anaerobic species such as Gardnerella vaginalis, Bacteroides species, Mobiluncus species, Ureaplasma urealyticum, and Mycoplasma hominis. Bacterial vaginosis can be diagnosed based on three out of four signs of Amsel's criteria including greyish-white vaginal discharge of uniform texture, an increase in vaginal pH above 4.5, presence of clue cells, and a positive whiff test. Gram-staining vaginal secretions confirms diagnosis. Bacterial vaginosis may increase the risk of pre-term labor in pregnant women. Vulvovaginal candidiasis, or vaginal yeast infection, is a fungal infection which occurs due to dysbiosis of the vaginal microbiome. The causative organism is Candida albicans. Signs and symptoms include vaginal itching, burning, pain, and a white "cottage cheese" discharge indicate a vaginal yeast infection. Vaginal yeast infections seemed to be triggered when C. albicans switches from the typical unicellular yeast form to a hyphal form. Dysbiosis of the vaginal microbiome is often caused by antibiotic therapy which wipes out the prominent lactobacilli species, allowing other species to become dominant. Hormonal changes, douching, or even bacteriophage introduced from a sexual partner's microbiome may also cause vaginal dysbiosis.

Exam Name

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) What is the innermost layer of the heart? A) pericardium B) cardium C) endocardium D) myocardium E) epicardium

2) Which of the following describes how blood travels through the heart? A) left atrium, right atrium, lungs, left ventricle, right ventricle, rest of the body B) left atrium, left ventricle, right atrium, right ventricle, lungs, rest of the body C) left atrium, left ventricle, lungs, right atrium, right ventricle, rest of the body D) right atrium, right ventricle, lungs, left atrium, left ventricle, rest of the body E) right atrium, left atrium, lungs, right ventricle, left ventricle, rest of the body

3) How does blood enter the heart? A) through the pulmonary arteries B) from the aorta C) by means of the capillaries surrounding the heart D) as paracardial fluid E) via the vena cava

4) Which of the following numbers represents arterioles?

A) 1

B) 2

C) 3

D) 4

E) 5

5) What is lymph? A) protein-rich blood plasma that has left capillaries B) thick carbohydrate matrix that supports cells in various tissues of the body C) the portion of blood that contains red blood cells D) the portion of blood that contains white blood cells and platelets E) the layer of lipids that collects under the skin for protection and insulation 6) After excess lymph drains from our tissues, it is shuttled to the lymph nodes and waste filtering and pathogen detection take place. A) spleen B) MALT tissue C) pancreas D) kidneys E) body tissues lacking sufficient lymph

, where

7) What happens if lymph is not collected? A) blood clots form B) hemorrhaging C) liver toxicity D) anemia E) edema

8) Which of the following is not a risk factor for developing sepsis? A) blunt force trauma B) nervous system infection C) chronic health issues such as cancer, diabetes, AIDS, and cardiovascular disease D) a wound E) recent surgery or invasive procedures

9) Which of the following is not a sign of sepsis? A) increased respiratory rate (more than 20 breaths per minute) B) increased white blood cell count C) rapid heart rate (more than 90 beats per minute) D) dilated pupils E) body temperature above 101°F (38.3°C) or below 96.8°F (36°C)

10) What is currently the most crucial way of reducing incidence of dengue, yellow fever, chikungunya, and Zika? A) increasing the availability of current vaccines B) providing better quality health care C) control mosquito levels D) avoid areas with high prevalence of these diseases E) educate the public about safe sex and condom use

10)

11) Why is the second stage of a dengue infection of concern? A) Hemorrhagic features may develop and lead to shock, organ failure, and eventually death. B) A high fever can lead to dehydration. C) Body aches and extreme abdominal pain can indicate an intestinal perforation. D) Vomiting can lead to dehydration. E) Nausea can be a symptom of the virus getting past the blood brain barrier, infecting the brain, and quickly killing the patient.

11)

12) Areas with a high population and low vaccination rates are susceptible to which type of transmission for yellow fever? A) intermediate B) jungle C) urban D) jungle, intermediate, and urban E) jungle and intermediate

12)

13) How can a chikungunya infection be differentiated from a dengue infection? A) Differentiation is based on symptoms due to the two presenting quite differently. B) stool analysis C) microscopic analysis of the blood D) liver biopsy E) blood tests that identify viral antigens, viral RNA, or patient antibodies to the virus

13)

14) A man and women honeymooned in Brazil and both came down with mild symptoms of a Zika infection upon returning home. How long should the couple wait to start a family based on this information? A) If they are in love they shouldn't wait. B) 1 year C) 6 months D) 8 weeks E) 3 months

14)

15) Which of the following would limit your possible exposure to the Lassa virus? A) not eating bushmeat B) using insect repellant C) keeping a rodent-free home D) avoiding sexual intercourse E) not eating anything that hasn't been well cooked

15)

16) The nickname "the kissing disease" refers to an infection caused by which pathogen? A) Epstein-Barr virus B) Lassa virus C) human immunodeficiency virus D) Ebola virus E) Marburg virus

16)

17) Burkitt's lymphoma is a possible complication of which disease? A) Marburg virus B) Ebola virus C) Lassa virus D) Epstein-Barr virus E) human immunodeficiency virus

17)

18) Which stage marks the progression of HIV to AIDS? A) stage I B) stage II C) stage III

18)

D) stage IV

E) stage V

19) An antiretroviral regimen usually consists of two reverse transcriptase inhibitors and a(n) A) protease inhibitor. B) integrase inhibitor. C) reverse transcriptase inhibitor. D) protease inhibitor, integrase inhibitor, or reverse transcriptase inhibitor. E) protease inhibitor or integrase inhibitor.

19)

20) When is the human T lymphotropic virus typically detected in a patient? A) Typically screened for when memory loss symptoms present B) The sores that develop in stage 2 give it away. C) Patient develops cancer or donates blood. D) It can only be detected postmortem. E) Initial symptoms of infection are a clear indicator.

20)

21) Which form of a Yersinia pestis infection can result in acral gangrene caused by intravascular coagulation? A) bubonic plague B) hepatic plague C) pneumonic plague D) septicemic plague E) cardiatic plague

21)

22) Which of the following figures is associated with a Yersinia pestis infection? A)

22)

23) Which of the following would not be the origin of the bacteremia leading to endocarditis? A) pneumonia B) infected gums C) skin abscesses D) venous catheters E) urinary tract infections

23)

24) Which of the following is one of the most common agents to cause endocarditis? A) Borrelia burgdorferi B) Rickettsia rickettsii C) Yersinia pestis D) Staphylococcus aureus E) Francisella tularensis

24)

25) Which of the following events does not put you at risk for contracting a Francisella tularensis infection? A) taking away a wounded rabbit your cat brought back for you B) adopting a dog from an animal shelter C) removing an injured squirrel from the road in front of your house D) cleaning a deer that you just shot E) a tick bite while out camping

25)

26) Why are early symptoms of a Francisella tularensis infection often difficult to diagnose? A) Early symptoms can vary based on how the bacteria are transmitted. B) Symptoms are often mild and go unnoticed. C) The bacteria do not grow in culture. D) Patient symptoms are the only indication that leads to a diagnosis. E) Symptoms progress so slowly it can be months before the patient seeks medical care.

26)

27) Erythema migrans often develops as a result of what infection? A) Francisella tularensis B) Borrelia burgdorferi C) Rickettsia rickettsii D) Staphylococcus aureus E) Yersinia pestis

27)

28) Which of the following is not a reason Rocky Mountain spotted fever should be diagnosed within the first few days of an infection? A) Untreated cases can be fatal in as few as eight days. B) It may cause blood vessel damage that impacts circulation to the arms and legs. C) A schizophrenia-like illness or mood disturbances may result. D) Fatal organ or brain bleeding may occur. E) Limb amputation may be required due to necrosis.

28)

29) Why are ehrlichiosis and anaplasmosis of concern? A) Both are fatal. B) Treatment is long and difficult for both. C) Areas of infection are spreading to other countries. D) Both produce major signs that can be permanent. E) Incidence of both is increasing.

29)

30) Which of the following ways can candidiasis be contracted? A) kidney dialysis or intravenous lines B) intravenous lines or surgery C) surgery, central venous catheters, kidney dialysis, or intravenous lines D) surgery or central venous catheters E) central venous catheters or kidney dialysis

30)

31) Who is primarily at risk for a candidiasis infection? A) immunocompromised individuals who have underlying conditions such as cancer, diabetes mellitus, AIDS, or who are taking medication that suppresses the immune system B) patients with long hospital stays C) patients with cancer D) elderly patients E) patients confined to a bed

31)

32) Which of the following infections presents with three stages: a cold stage hallmarked by shivering and a sensation of cold, a hot stage with fever, and a sweating stage? A) Rocky Mountain spotted fever B) invasive candidiasis C) malaria D) Lyme disease E) ehrlichiosis

32)

33) When traveling to regions where malaria is common, what is the recommendation? A) Preventive antimalarial drugs should be taken daily while traveling in endemic areas. B) If you get malaria buy some antimalarial drugs while traveling. C) Get vaccinated for malaria before traveling. D) Spray your clothes with insecticide each morning you are traveling in endemic areas. E) Buy a bed net while traveling.

33)

34) Complicated malaria is more common in which of the following patient populations? A) young patients B) young or elderly patients, as well as those who are pregnant or immunocompromised C) elderly patients D) young adult patients E) immunocompromised patients

34)

35) Mosquitoes infected with Plasmodium pass on which of the following to the host? A) sporozoites B) trophozoites C) gametocytes D) merozoites E) schizonts

35)

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 36) Septic shock can cause disseminated intravascular coagulation that blocks blood flow and promotes organ failure and tissue necrosis.

36)

37) Dengue fever, yellow fever and malaria are all caused by different RNA viruses.

37)

38) Polyarthralgia is a condition experience by patients with dengue fever.

38)

39) The Ebola virus is a single-stranded RNA virus.

39)

40) Endocarditis is mainly seen in people who have damaged, abnormal, or artificial heart valves or other heart defects.

40)

41) Rocky Mountain spotted fever continues to be isolated to those states that border the Rocky Mountains.

41)

42) Individuals more susceptible to fungal disease, such as AIDS patients, may be placed on antifungal medication as a preventive measure.

42)

43) Mosquitoes that bite an infected patient take up sporozoites, which goes through another growth cycle that culminates in the formation of the gametocytes that can perpetuate the infection cycle in another human.

43)

ESSAY. Write your answer in the space provided or on a separate sheet of paper. 44) Describe how you would initially manage a patient with sepsis and then what additional steps you would take if the patient needed to be put on life support. 45) What three outcomes result from a human T lymphotropic virus infection? 46) Although uncomplicated malaria presents with mild symptoms, complicated malaria can have a number of signs. What are they?

Answer Key Testname: UNTITLED36

1) C 2) D 3) E 4) A 5) A 6) B 7) E 8) D 9) D 10) C 11) A 12) C 13) E 14) C 15) C 16) A 17) D 18) C 19) D 20) C 21) D 22) A 23) A 24) D 25) B 26) A 27) B 28) C 29) E 30) C 31) A 32) C 33) A 34) B 35) A 36) TRUE 37) FALSE 38) FALSE 39) TRUE 40) TRUE 41) FALSE 42) TRUE 43) FALSE 44) Managing sepsis mainly involves reducing system-wide inflammation, regulating body temperature, stabilizing blood pressure, and increasing blood oxygen levels. If the sepsis case is caused by a nonviral pathogen, then intravenous antimicrobial drugs may also be administered. Patients with severe sepsis are often put on life support until they are fully stabilized and the condition starts to resolve. Life support care often includes intubation, mechanical ventilation, sedation, and analgesia (pain management/relief).

Answer Key Testname: UNTITLED36

45) 1. Virus-infected T cells grow abnormally and result in adult T cell leukemia or lymphoma. 2. Infected T cells may produce abundant interferon, creating inflammatory responses to the central nervous system, ter HTLV-1-associated myelopathy (HAM). 3. HTLV infection can result in unchecked or opportunistic infections due to the decrease in functioning leukocytes. 46) Complicated malaria can present with anemia, low blood pressure (hypotension), low blood glucose (hypoglycemia), and/or excessive acidity of the blood (acidosis). Kidney failure, acute respiratory distress syndrome, and malarial infection of the brain are also possible in severe cases.