Quiz

QUIZ

1. What least likely affects the contagiousness of an infectious disease?

a. How deadly the disease is b. Characteristics of the host c. Characteristics of the pathogen d. Route of infectivity

Answer: a. Each of these will affect the contagiousness of an infectious disease except for the deadliness of the disease itself. Minor or major infections can be equally contagious.

2. What disease is infectious in origin but noncommunicable?

a. Ebola virus b. Clostridium tetani or tetanus c. Hepatitis D d. Cholera

Answer: b. Clostridium tetani causes tetanus, which comes from soil spores. The disease comes through an open wound but cannot be passed from person to person or from animal to person. The other diseases are directly or indirectly communicable.

3. What is true of Koch’s original postulates? a. It is valid in all cases of an infectious disease. b. It applies only to bacterial diseases. c. There are several exceptions to these postulates. d. The only postulate that is incorrect is the second postulate.

Answer: c. There are several exceptions to these postulates that make it difficult for them to be used for all infectious diseases. It can apply to many diseases that are not bacterial. More than one postulate can be invalid.

4. What are the molecular Koch’s postulates most based on?

a. The ability to grow a pathogen in tissue culture rather than pure culture. b. The presence of different metabolic effects in different pathogens. c. The presence of host effects that confer disease resistance. d. The presence of genes that confer pathogenicity.

Answer: d. The molecular Koch’s postulates specifically talk about the presence of certain genes that confer pathogenicity in the offending organisms.

5. Which type of organism will have spike proteins that act in pathogen adherence?

a. Viruses b. Bacteria c. Protozoans d. Fungi

Answer: a. Viruses will have spike proteins that affect their ability to adhere to the host. This is not seen in other pathogens.

6. What is least likely to be an adhesion factor in a bacterial infection?

a. Biofilm formation b. Capsules c. Barbs d. Glycocalyces

Answer: c. Each of these is an adhesion factor in a bacterial infection except for barbs, which are seen in protozoal infections.

7. Which of the following exotoxins in bacteria does not directly target an intracellular process in the cell but is a superantigen instead?

a. Diphtheria toxin b. Botulinum toxin c. Cholera toxin d. Staphylococcus aureus toxin

Answer: d. Certain toxins from strains of Staphylococcus aureus will lead to toxic shock syndrome from specific activation of the immune system because the toxin is a superantigen. The others are intracellular targeting toxins.

8. What is the activity of the exotoxins that are also phospholipases?

a. The degrade the host cell membrane b. They create pores in the host cell membrane c. They activate cyclic AMP d. They act as superantigens to the host immune system

Answer: a. Phospholipases are made by certain bacteria. They degrade the cell wall, killing the host cell.

9. What is the name of a disease that has impact throughout the world?

a. Sporadic disease b. Endemic disease c. Epidemic disease d. Pandemic disease

Answer: d. A pandemic disease is one that has a major impact throughout the world.

10. Which spread of a disease involves no specific source because each infected person becomes infectious themselves?

a. Point source spread b. Intermittent source spread c. Propagated spread d. Continuous source spread

Answer: c. With propagated spread, there is person to person transmission of a disease in which each infected person becomes a source of the infection.