Table of Contents: First Quarter: Nine Items A. B. C. D. E. F. G. H. I.
Scientific Method Lab Microscope Lab One Microscope Lab Two Microscope Lab Three Cork Drawing Animal Cell Drawing Plant Cell Drawing Cell Diffusion Lab Mitosis Drawing
Third Quarter: Eleven Items A. B. C. D. E. F. G. H. I. J.
Natural Selection Lab Phylogenetic Tree Drawing Clam Lab Report Phylum Mollusca Drawing Worm Lab Report Worm Coloring Crayfish Lab Report Starfish Lab Report Starfish Coloring Phylogenetic Tree of Vertebrate Species Drawing K. Phylum Chordata Coloring
Second Quarter: Ten Items A. B. C. D. E. F. G. H. I. J.
Meiosis Drawing Mendelian Genetics Lab One Mendelian Genetics Lab Two Mendelian Genetics Lab Three Mendelian Genetics Lab Four DNA Model and Replication Lab RNA Transcription Lab RNA Translation Lab Model Assessment Questions Classification Lab
Fourth Quarter: Seven Items A. B. C. D. E. F. G.
Perch Lab Report Frog Lab Report Frog Coloring Heart Rate Lab Blood Type Lab Nutrition Lab Reflection Essay
Total Item Number: Thirty-Nine
Christopher Mr. Snyder Biology 1 August, 2008
Lab Report Sheet Part A: Observations
Pupae: Description !
The pupae are small, tubular organisms, reddish brown in color, with spiral markings that lead across the body, to air holes on each side. They are entirely still.
!
Nasonia: Description !
!
The Nasonia are almost unobservably small flies, yellowish of appearance, with various white splotches showing. They do not appear multi—segmental from my viewpoint, and their heads are roughly a fourth the size of their bodies.
Behavior: !
Immediately after being introduced to the pupae, the Nasonia attacked them viscously, stinging and stabbing from above.
Part B: Hypothesis
!
The Nasonia, when introduced to the pupae, will quickly become vicious, stinging and stabbing at the pupae, in an attempt to eat them. This will probably be caused due hunger from their long hibernation.
Part C: Experimental Design
!
In order to test my hypothesis, I will designate one pair of pupae my control group, and place them in the controlled environment of a test tube. The other group I will designate as my experimental group, and place in a test tube alongside Nasonia. After 14 days of observation, I will end my experiment.
Part D: Data Collection !
!
Part E: Conclusion After Collecting data, you should make a conclusion about the relationship between the pupae and the Nasonia
Analysis 1. Was you original hypothesis correct or incorrect? Your teacher may have made a class list of hypotheses from each team. if so, have you truly disproven any of the hypotheses that differ from yours? !
My original hypothesis was incorrect— but the results proved that several of the other hypotheses were also incorrect.
2. Parasitism is defined as follows: One organism (the host) receives no benefits and is often injured while supplying nutrients and/or shelter for the other organism (the parasite). Based on what you observed throughout this activity, explain why Nasonia are called parasites. !
Nasonia are called parasites because they kill their host giving it nothing in return, and inject their young into further hosts.
3. The pupae in this activity are from the organism know as Sarcophoga. What do you think the Sarcophoga do after they emerge as adults. !
They lay their own eggs, beginning the Sarcophoga life cycle all over again‌
4. Before the Sarcophoga formed a pupae, it was a wormlike creature called a larvae. You probably call them maggots. Can you think of another insect that has a life cycle like the Sarcophoga? !
The butterfly has a life cycle like the Sarcophoga.
5. How do you think that the young Nasonia got into the Sarcophoga pupae? !
Through the air holes at each end of the Sarcophoga.
6. Reflecting on this activity, you should now be familiar with the steps that scientists take when performing research. What are the steps of the scientific method that you employ in this activity? !
Some of the steps are: forming a hypothesis, devising an experiment, making observations, and formating data.
7. Throughout this activity, you were able to observe the Nasonia at varying developmental stages. Describe the Nasonia life cycle. !
The nasonia goes from egg, to larvae, to pupae, to adult, and then lays eggs.
Christopher Mr. Snyder Biology 1 August, 2008
Activity One
Constructing a Water Lens Microscope For Centuries scientists have used transparent materials, having at least one curved surface, to make lenses to form magnified or reduced images, or to concentrate or spread light rays. In this activity you will construct such a lens— out of water—and mount it on a card to function as a simple, single-lens microscope. What you need per group: ! ! ! ! !
Four paper card with center holes One cup containing water One Pipet Printed magazine images; color and black/white transparent tape
What to do‌ 1. Carefully place a piece of transparent tape so that it covers the center hole on the card provided. 2. Carefully place a drop of water onto the transparent tape covering the hole on the card. Keep adding small drops of water until the enlarging drop fills the hole. 3. Describe, draw, and label the created lens through this process below: !
4. Now use this water lens to view the type of this page. Record you your observations below: !
Text viewed under the water lens is magnified approximately twice it's size, but becomes extremely blurry.
5. Use your water lens microscope to view printed black/white and color images supplied by your teacher. Can you determine how these images are made? Describe your observations below: !
Text viewed under the water lens is magnified approximately twice it's size, but becomes extremely blurry.
6. What is your definition of a lens and a microscope? Definition of a lens: !
A lens is something which bends light to magnify an object
Definition of a microscope !
A microscope is an object intended to view things to small for, or invisible to, the naked eye.
Christopher Mr. Snyder Biology 1 August, 2008
Activity Two
Using the Compound Microscope What you need per group: ! ! ! ! ! ! !
Compound Microscope Coverslip Forceps glass microscope slide Newsprint Scissors Student Information Sheet #1 Visual Guide to the Microscope
What to Do… Making a new newsprint: 1. Use scissors to carefully cut out a short newsprint word (not a headline word) containing the letters “e”, or “r”. 2. Place a single drop of water in the center of a clear microscope slide. 3. Carefully lower a coverslip at an angle onto the wetted paper being careful not to trap air bubbles. Observing a Wet Mount of Newsprint 1. Place the slice on the stage of the compound microscope, with the center of the upright coverslip area centered over the hole in the stage. Position the slide using stage clips so that the newsprint is facing you and can be read right side up. Record what you observe below: Image Orientation: !
Image appearance to the naked eye on the microscope stage
2. Adjust the light source (flat mirror surface or illuminator) and diaphragm (disk or iris) so that light passes up through the paper. You should be able to see a circle of light when you look into the eyepiece. 3. Position the lowest power objective into the optical path by rotating the nosepiece. You will feel a “click” when the objective is correctly positioned. Use the coarse adjustment knob to lower the objective to approximately 1 inch (2.5 cm) above the stage. 4. Look through the eyepiece and slowly raise the objective by turning the coarse adjustment knob counter–clock–wise (i.e towards you) until the image is in focus. Then use the fine adjustment knob to bring the image into sharp focus. Image Description: !
The image resembles a picture from outer space; swirls of color and vibrancy radiate from orange to green, in every shape and size. Some are spiral, others are flat, some tall, some short. Regardless, in every way a stunning sight.
Image appearance: !
5. In the newsprint image formed by the microscope oriented the same as when you observe it with your naked eye? Move the slide downward. Which way does the image move? Move the slide to the right and then the left. Which way does the image move? !
Christopher Mr. Snyder Biology 1 August, 2008
Activity Three
Determining Magnification and size In Activity One, you made observations using a single–lens microscope of your own construction. A basic compound microscope has two lens systems: an “Objective” lens (i.e. closest to the thing being viewed), and an “ocular” lens (i.e. closest to the eye). Magnification is the ratio of the apparent size of a magnified object to its true size. If a lens produces an image of a viewed object that is four times its real size, its magnification is capability of power is “4x” In a compound magnifying system, magnification takes place in two stages. The objective lens first projects a magnified image of the object to a fixed position about 1 cm below the top of the viewing tube in the microscope. The eyepiece, positioned in the body tube above this projected image, re–magnifies into a second image that the eye observes. Thus the total magnification of the microscope is found by multiplying the power of the objective by that of the eyepiece.
What you need per group: ! ! ! !
Compound microscope Prepared wetmount of newsprint (from Activity Two) Ruled 1mm graph paper (1 cm, square) Ruler, metric
Determining Magnification 1. Record the total magnification of the lowest power objective of your microscope used to view newsprint in Activity Two below: Lowest power magnification: !
40x
2. Change to a higher power objective. Exercise care when rotating any high– power objective into the optical path. Make sure that the higher objective will not touch the coverslip. With most newer microscopes, you should be able to rotate the higher power objective into place and observe an image that will only need sharpening using the fine adjustment knob. If not, turn the coarse adjustment knob clockwise to “rack down” the objective until it is no closer than 1–2 mm from the coverslip surface. Then use the fine–adjustment knob, to sharpen the focus. Do not use the coarse adjustment knob to focus any high–power objective. Is the light brighter or darker? After changing objective lenses, readjust the diaphragm for best lighting. You will need more light. (i.e. a wiser diaphragm opening )at higher objective lens magnifications. 3. Below, draw comparative drawings of the newsprint image at both lowest and next highest magnification of your compound microscope. Also record total magnification for each. !
Determining Field Diameter and Object Size
4. To determine the diameter of a particular field–of–view, place a piece of 1mm ruled graph paper over the hole in the stage. Focus using a low power objective (i.e. 4X or 10x) to obtain a clear image of the divisions of the ruler or the rules of the graph paper. You should observe an image like the one below. !
5. For Each object,, draw the observed field of view and determine its field size below: !
6. Knowing the field diameter for a particular objective lens can aid in measuring length. If an organism is about one–quarter the length of the field diameter at 100x it is approximately 400qm in length. Using the field diameter as an aid in estimating the width of the newsprint letter you are observing and record it below: !
7. Use a ruler to measure the the true size, in millimeters (mm), of the width of the actual newsprint letter and record it below. They should also take eyepiece measurements of the apparent image of the letter “e” ! ! !
Actual (true) size = 1 mm Apparent Size— lowest magnification = 4 mm Apparent Size— next highest magnification = 400 mm
8. Next, Calculate the magnification ration for both eyepiece magnification views of the newsprint letter measure based upon your previously recorded measurements. For example What is the magnification ratio of an apparent image at the lowest power total magnification (40x) is 4 mm if it measures 4mm? Magnification = 160 mm (Tube Length) divided by Apparent Size. 160 mm divided by 4 mm = 40 :1 ratio. Tube length is the distance between the objective and eyepiece lenses. !
Christopher Mr. Snyder Biology 1 August, 2008
Agar Experiment
Objectives: • Determine the extent and rate of diffusion into three different sized agar cubes • Calculate the surface area to volume ratio for each ager cubes • Observe the relationship between cell size and extent of diffusion in the ager cubes • Understand the necessity for microscopic cell sizes
Materials: • 1 3 cm x 3 cm x 6 cm phenolphthalein agar block • 1 Plastic knife • 1 Plastic cup • Diffusion medium
Procedure: 1. Obtain a 3 cm x 3 cm x 6 cm agar block from your teacher. Using a plastic knife, trim this piece to a cube 3 cm!. Repeat this procedure to make a 2cm! cube and a 1cm! cube 2. Place the three cubes carefully into a plastic cup. Add diffusion medium until
the cup is approximately half full. Be sure the cubes are completely submerged. Using a plastic spoon, keep the cubes submerged for 10 minutes, turning them occasionally. Be careful not to scratch any surface of the cubes 3. As the cubes soak, calculate the surface area, volume, and surface area to volume ratio for each cube. Record these values in Data Table 1. Use the following formulas:
•
surface area = length x width x number of sides
•
volume = length x width
4. After 10 minutes, use a spoon to remove the agar cubes and carefully blot them dry on a paper towel. Then, cut the cubes in half. Not the color change from red or pink to clear that indicates the diffusion of diffusion medium into the cube. 5. Using a metric ruler, measure the distance in centimeters that the diffusion medium diffused into each cube. Record the data in Data Table 2. Next, record the total time of diffusion. Finally, calculate and record the rate of diffusion for each cube as centimeters per minute. 6. Examine the extent of diffusion for reach cube. Visually estimate the percentage of diffusion into the cube. Record your estimate in Data Table 3 7. Calculate the volume of the portion of each cube that has not changed color. Record your results in Data Table 3. 8. Calculate the extent of actual diffusion into each cube as a percent of the total volume.
Graphs:
Date Table 1: Ager Cubes Cube Size
Surface Area(cm)
Volume (cm!)
Surface Area/Volume
3cm!
54
27
2:1
2cm!
24
8
3:1
1cm!
06
1
6:1
Date Table 2: Rate of Diffusion
Cube Size
Depth of Diffusion
Time (min.)
Rate of Diffusion (per min.)
3cm!
0.1
10
.01
2cm!
0.5
10
.05
1cm!
1.0
10
.10
Data Table 3: Extent of Diffusion
Cube Size
Estimation of Total Volume Cube Which of Cube has changed Color
Volume of Cube Which has not Changed Color
Percent Volume of Cube Which Changed Color (Extent of Diffusion)
3cm!
27 cm!
10%
24.3
10%
2cm!
8 cm!
50%
4.0
50%
1cm!
1 cm!
100%
0
100%
Assessment: The agar you used to make your cubes contained phenolphthalein and had a pH of greater than 9. Explain how the use of a pH indicator allowed you to visualize the extent of diffusion into the cubes ! The acidic diffusion medium causes the pH's color to change from pink to clear. 2. According to Data Table 2, into which cube did the diffusion medium diffuse the deepest? ! The 1cm! cube Into what cube did the medium diffuse the most by volume? ! The 1cm! cube Examine your data in Data Table 2 for a relationship between cube size and the rate of diffusion into the cube. Make a generalized statement about the relationship between cell size and the rate of diffusion. ! The larger the cell size, the slower the rate of diffusion 5. Examine your data in Data Table 1. Describe what happens to the surface area , the volume, and the ration between the two values. ! The volume cubes, the surface area squares, and the ratio increases toward the the volume. 6. If each cube represents a living cell and the diffusion medium a substance needed within the cell, what problem might exist for the largest cell? ! The timely moving of substances across its cell membrane, the amount of substances which could enters, and (in some cases) the capacity for photosynthesis. 7. According to the results of your investigation, describe the characteristics of cell size, surface area, and surface are to volume ration which best meet the diffusion needs of living cells ! Cell size would be small, surface area would be wold be large, and surface area to volume ratio would be large.
8. The size of some human human cells is 0.1 mm. Using the formulas in this activity, calculate the surface area to volume ration of such a cell (assume the cell is a 0.1 mm cube). Describe the extent and rate of diffusion into this living cell as compared to the small ager cube. ! The surface area to volume ratio is 600 to 1. !
The rate of diffusion for the living cell would be much faster than that of the ager cube, due the latter's lesser surface–area–to–volume ratio.
9. Is diffusion the only method in which substances enter a cell? If not, what factors are not accounted for in the simulation. ! Active transport, and any type of facilitated diffusion. 10. Osmosis is a specialized form of diffusion. Research Osmosis and create a venn diagram comparing osmosis to diffusion. !
Christopher Long Biology I Mr. Snyder October 20th, 2008
Activity One
Mendel and the Laws of Chance; Calculation of Genetic Ratios: A great scientist once wrote… “all science is measurement”. In genetics, much of that which is measured concerns the ratios of different phenotypes (outward appearances) and genotypes (genetic makeup). These genetic relationships arise from probability relationships—the chance–segregation and assortment of genes in games, and their chance combination to form a zygote (a diploid cell resulting from the union of two gametes). In this activity, you explore how the determination of genetic ratios is derived from two basic laws of chance. In applying mathematics to the study of genetics, Mendel was stating that the laws of chance apply to biology as well as they do to the physical sciences—a radical concept for the times!
Laws of Chance: Materials needed per group: ! !
Two double-sided plastic “coins”—marked “heads” and “tails” Student Study and Analysis Sheet (one per student)
Toss the two–sided coin. The chance that it will turn up “heads” is !. If two coins are tossed, the chance that both will turn up “heads” is again !. The chance that the second will also turn up “heads” is !. The chance that both will turn up “heads” is ! x ! or ". Summary: The probability of two independent events occurring together is simply the probability of one occurring alone multiplied by the probability of the other occurring alone. We can diagram this probability relationship in a checkerboard—a Punnet Square (as below), which indicates that the combination in each square has an equal, independent chance of occurring.
!
Note: The Punnet square was named after an english geneticist who first used this sort of diagram for the analysis of genetically determined traits.
1. What would the the probability (chance) be, if there were three plastic “coins”? !
!
2. Place two plastic “coins” in a shaker cup. Shake and toss the pieces onto the table top 100 times. Keep track of the results: record totals in the spaces below. Do the results come close to those predicted by the Punnet Square. ! ! !
“Heads”/“Heads”: “Tails”/”Tails”: “Tails”/“Heads” and “Heads”/“Tails”:
20 25 55
3. Suppose you toss both plastic coins 1,000 times instead of 100. What would this larger sample allow? !
The odds would even out—the ratio of your own findings would draw nearer to the expected ratio.
Calculation of Genetic Ratios: On the basis of Mendelian principles, a diploid (double set of chromosomes) adult of genetic constitution Aa may give rise to two games, A, and a. If the genetic constitution of the parents is not given, two possible explanations (hypotheses) exist which can account for the presence of phenotypes. A or a in the offspring. The answer, in terms of probability is to assume that the parents Aa produce two types of gametes, A and a, equally well and the aa parent produces only one type of gamete, a. Any combination of gametes depends upon the frequency or probability of each type of gamete furnished by the parents. Thus the formation of a zygote is the result of two independent events (two gametes), each with their own probabilities, which now occur together. Summary: The probability that a particular zygote will be formed is equal to the product of the probabilities of the gametes that compose it. 4. Complete the two checker boards below to calculate the values: !
5. Complete the following statement for the Aa x Aa cross: !
How many possible kinds of zygotes can be formed? 4
!
The probability that the A phenotype will occur? !
!
The probability that a zygote can be heterozygous (i.e. Aa or aA) "
!
The probability that a zygote can be either AA, Aa, or aA? !
!
The probability that a zygote can be either AA, Aa, or aA? !
!
The probability that a zygote can be either AA, Aa, or aA? 1
!
What are the genotype and phenotype ratios? Genotypic Ratio: 1AA:1Aa:1aA:1aa Phenotypic Ratio: 3A:1a
6. Complete the following statement for the Aa x aa cross: !
Do both genotypes occur with equal frequency? Yes
!
The probability that the A phenotype will occur? !
!
What are the genotype and phenotype ratios? Genotypic Ratio: 1Aa:1aa Phenotypic Ratio: 1A:1a
Christopher Long Biology I Mr. Snyder October 20th, 2008
Activity Two
A Monohybrid Cross This activity investigates crosses between pea plants that are different in but a single characteristic (gene difference)—a monohybrid cross. Materials needed per group: ! !
! !
Cup shaker Four discs representing gamete cells. ! Two Red Allele Discs each having W for the purple flow on each side. ! Two Red Allele Discs each having w for the white flow on each side. Student Study and Analysis Sheet One wax pen
Note: A pea plant homozygous for purple flower color is represented by WW in genetic shorthand. The gene for purple flow coloring is designate W because of a convention by which geneticists, in indicating a pair of alleles, use the first letter of the less common form (white). The capital indicated the dominant,, the lowercase the recessive. Use the wax pen provided to write the allele type (W or w) on Each side of the disc.
Read and become familiar with the information presented in the Student Study Sheet. 1. Place two W allele disc in the cup, representing the union (fertilization) of male and female gametes. Shake and toss them onto the table. Repeat nine more times. Record your results (genotypes, phenotype) below: ! !
Genotype: 1WW Phenotype: 1w
2. Repeat Step 1 (above), but this place two w allele discs in the cup. Shake and toss. Repeat nine additional times. Record the genotype and phenotype below: ! !
Genotype: 1WW Phenotype: 1w
3. Cross two purple (W) plants created from zygote unions in Step 7 by allowing them to self–pollinate as Mendel did. Draw a Punnet square and record the genotypes and phenotypes. !
4. Write a statement that explains why these plants would continue to “breed true” !
The plant continue to “breed true” because each has only one distinct factor for each characteristic.
5. If white plants (w) were substituted for purple (W), would there be any change in the expected outcome? !
If white plants were substituted for purple plants, there would be no change in the expected outcome, besides a different phenotype.
Christopher Long Biology I Mr. Snyder October 20th, 2008
Activity Three
Principle of Segregation In this activity you will study single gene differences in various monohybrid crosses that led Mendel to the discovery of the Principle of Segregation—the ability to predict the segregation between two different alleles in a single gene pair and their behavior in each generation. Materials needed per group: ! ! ! ! ! !
Two yellow–colored plastic discs—representing “purebred” (homozygous) yellow pod color trait One green–colored plastic disc—representing “purebred” (homozygous) green pod color trait One red–colored plastic disc—representing “purebred” (homozygous) purple flower trait One blue colored plastic disc Clear sticky tape (not provided) Student Study and Analysis Sheet
Mendel conducted experiments on seven traits (see table 1) whose characteristics (itself and its alternate) were clearly defined. This activity will simulate crosses among two of these: flower and pod color. 1. Simulate a cross between a plant homozygous (GG) for the green pod color trait (green–colored plastic disk) by crossing it with another homozygous (gg) for yellow pods (yellow–colored plastic disc). 2. Conduct another simulated cross, this time using red–colored discs to represent a plant hozygous (WW) purple–colored flowers with yellow– colored discs to represent a plant homozygous (ww) white–colored flowers. Secure plastic discs with sticky tape. 3. What generation do both these “disc crosses” represent? !
They represent the F1 generation
4. Hold each disc (representing a cross result) set up to the light and record the “dominant” observed color below. ! !
Cross GG x gg: Green Cross WW x ww: Red
5. What phenotypic trait is hidden in each cross? ! !
Cross GG x gg: Yellow pod color Cross WW x ww: White flower color
6. Describe the relationship of “dominant” and “hidden” traits !
Dominant traits are dominant, and conceal hidden traits, which are recessive
7. Complete the Punnet Squares below, writing in both genotype and phenotype for each of the above crosses. !
8. Write a statement that describes each cross. !
The offspring resulting from each cross will be be heterozygous
9. Use the information from Step 6 to allow each plant variety (pod and flower color) to self pollinate. Can you (like Mendel) predict the results? Complete another Punnet square for each cross—record phenotype and genotype. !
10.In what ratio do the dominant and recessive traits appear? !
3:1
Is there a similar relationship concerning all of the seven traits studied by Mendel? !
Yes
11. Use the results of your observations together with Mendel's actual laboratory to explain how recessives disappear so completely and then reappear again, always in constant proportions. !
In the F1 generation, heterozygous offspring are always created because both pairs of alleles for each trait are homozygous. Thus, the dominant phenotype shows. In the F2 generation, two pairs of heterozygous alleles are combined, which allows ! chance for recessive traits to re-emerge
12. Write a statement describing how Mendel probed the principle of segregation. !
Mendel saw the appearance and disappearance of traits and their constant proportions, and that this could be explained if hereditary characteristics were determined by discrete factors.
Christopher Long Biology I Mr. Snyder October 22nd, 2008
Activity Four
Understanding Dominance This activity investigates crosses between pea plants that are different in two trait characteristics, (a dihybrid cross) with each gene pair having one dominant and one recessive allele—and how each gene pair acts independently of the other. Phenotypes in the resultant generations will be, on average, in a ratio of 9:3:3:1 —testifying to the independence, or independent assortment of these two gene pairs. Materials needed per group: !
!
Two four-sided dice—each numbered side representing two gene pairs ! 1 = (RY) round yellow ! 2 = (Ry) round green ! 3 = (rY) wrinkled yellow ! 4 = (ry) wrinkled green Student Study and Analysis Sheet
1. Use table one to determine which traits (seed form and seed color) are dominant, and which are recessive: !
Dominant: round, yellow
!
Recessive: wrinkled, green
2. Predict the genotype and phenotype of the F1 generation that results from a cross of a plant homozygous for round (RR) and yellow (YY) is crossed with plant having wrinkled (rr) and green–colored (yy) peas. !
Genotype: RrYy
!
Phenotype: RY
3. Complete this Punnet Square for self fertilized F1 plant from the above cross to predict future phenotypes: !
!
Phenotypes: round–yellow, round–green, wrinkled–yellow, wrinkled–green
4. Use four–sided dice for Steps 27 through 28: !
Two four-sided dice—each numbered side representing two gene pairs ! 1 = (RY) round yellow ! 2 = (Ry) round green ! 3 = (rY) wrinkled yellow ! 4 = (ry) wrinkled green
Each die is read by matching the number visible on the point, correlated to the gamete designation above. Thus when two die are cast (simulating fertilization) the genotype of the organism is established. For example: a cast die indicate “4” and “1”. The corresponding genotype would be RrYy–round yellow. 5. Cast two dice 80 times (or as many times as your teacher directs) to arrive at organism genotypes. Tally likely phenotype combinations. ! ! ! !
round yellow: round green: wrinkled yellow: wrinkled green:
45 19 11 6
6. What is the phenotypic ratio? !
45RY:19Ry:11rY:6:ry
7. Add your data to that of the rest of the class; are the phenotypic ratios altered much? How do they compare with your Punnet square prediction? !
The phenotypic ratios are not altered much. They compare closely with my Punnet square prediction.
8. Write a statement that summarizes Mendel's principle of independent assortment based upon your classroom data and Punnet square prediction: !
The contrasting alleles which control a factor separate during the formation of gametes, and each is joined to another allele during the creation of a zygote.
Christopher Long Biology I Mr. Snyder October 20th, 2008
Genetics Lab:
DNA Molecule and Replication RNA Transcription RNA Translation
Materials Needed per Group: ! ! ! ! ! ! ! ! ! ! ! ! ! !
18 Black, deoxyribose molecule pieces 9 Blue, ribose molecule pieces 25 White, flexible phosphate molecule tubes 10 Red, guanine base tubes 4 Blue, thymine base tubes 8 Green, adenine base tubes 10 Black, cytosine base tubes 4 White, uracil base tubes 18 Solid, hydrogen bond connectors 3 Blue tRNA models 3 Black, amino acid models 2 White, rigid amino acid bonding tubes 1 Blue, ribosome model Chart (below) !
Nucleotide
Color
Adenine
Green
Cytosine
Black
Guanine
Red
Thymine
Blue
Uracil
White
Procedure Student should already have a basic understanding or organic molecules such as nucleic acids and proteins. Knowledge of cell structures an their functions may also save explanation time during the laboratory procedure. Part I: Making a DNA Chain: A. Laying down the tracks 1. Obtain eight white phosphate flexible model tubes and nine black deoxyribose sugar pieces. Connect these in a straight chain, so that the third, open, bonding site on each sugar is facing the same direction. Obtain eight more phosphate tubes with nine sugar pieces, and form a second chain with each extra bonding site facing the same direction. Set these chains parallel on the table in front of you so that the extra bonding sites are facing each other, forming a structure that resembles tracks of a railroad. (Figure 1).
A. Partially Completing the DNA Molecule 1. The open bonding site on each nucleotide's sugar is filled by a nitrogen base. DNA has four possible nitrogen bases, and they have been color coded for this investigation. Starting at the top of one of your phosphate sugar tracks, bond the following nitrogen bases, in order, to the strand: cytosine, thymine, adenine, cytosine, guanine, guanine, adenine, thymine, guanine. This strand is marked with an asterisk in figure 4 because it will be the single strand transcribed by the RNA in Part E.
2. The second chain of phosphate-sugar molecules also contains nitrogen bases, and they are aligned in a specific arrangement dependent on the first strand's patter. The nitrogen bases guanine and cytosine must always line up across from each other. Likewise, adenine and thymine will always match up. 3. Since the first nitrogen base on the top chain was cytosine the first nitrogen base on the bottom strand must be guanine. Place a guanine on the first deoxyribose of the bottom chain (Figure 4). Complete the bottom strand, placing the appropriate nitrogen base on each sugar that will correctly complement its opposing base.
4. Nitrogen base pairs join via hydrogen bonding to create the “railroad ties” that run between the phosphate-sugar “tracks”. Obtain nine hydrogen bonding plugs, and connect the two strands at their complementary nitrogen bases. This model is a portion of a DNA molecule. Part II: Messenger RNA and Transcription: A. Unzipping the DNA 1. In order for the information stored in the DNA to be used, the strand must temporarily separate at the hydrogen bonds that connect the complementary nitrogen bases. This model is a portion of a DNA molecule.
B. Preparing RNA Nucleotides 1. The DNA of a cell remains in the nucleus at all times, yet protein synthesis occurs in the cytoplasm. The information is transferred from the nucleus to the cytoplasm by a second type of nucleic acid, RNA. The sugar within RNA is called ribose and it contains one more hydroxyl group (-OH) than DNA's sugar, deoxyribose. Obtain nine blue ribose pieces from your kit, and connect a white flexible phosphate tube to each. Do not link the sugar– phosphate models in a chain, but leave them as individual sections. 2. Complete the nine RNA nucleotides by adding a nitrogen base to each. Remember from the introduction that thymine is not a possible nitrogen base in RNA, but that uracil is used instead to compliment adenine. To successfully continue with the procedure, you will ned to add two adenines, two guanines, two uracils, and three cytosines to your sugar phosphate combinations. B. Transcribing the mRNA 1. Using the “unzipped”, single strand of DNA, marked with asterisk in figure 2, and the hydrogen bond connectors, pair up the RNA nucleotides with their complementary DNA nitrogen bases. Recall that cytosine will pair with guanine, while adenine will pair with thymine of uracil.
2. Connect each nucleotide's phosphate group to the neighboring nucleotide's sugar.
3. Detach the RNA strand from the DNA strand at the hydrogen bond locations, allowing RNA to keep the bonds. This strand of ribonucleic acid is called messenger RNA (mRNA) because it carries the information stored on a DNA in the nucleus to a ribosome located in the cytoplasm. The mRNA is like a photographic negative of the original DNA single strand. Compare your mRNA to the complementary single strand of DNA, from Part B. Aside from uracil replaing theymine, and ribose replacing deoxyribose, the strands are identical 4. Using the remaining hydrogen bond connectors, reconnect two single DNA strands, and save your double stranded DNA model for further observations later in this investigation. Part III: Transfer RNA and Translation: A. Ribosomes and Codons 1. After seperation from the DNA, the mRNA exists the nucleus and parteners with a ribosome in the cytoplasm of a cell. Place your mRNA model on the plastice ribosome plate from your kit. 2. A ribosome recognizes three nucleotides at a time on the mRNA. The group of three nucleotides is called a codon, and codons spell out a message that will translate to a specifiec amino acid in the protein synthesis sequence. Your current chain of nine RNA nucleotides is actually considered three mRNA codons. Compare your codons to the illustration in figure 4.
B. Transfer RNA and Anticodons 1. A second type of RNA awaits the mRNA in the cytoplasm of the cell. Transfer RNA (tRNA) is a relatively small molecule that bonds to an amino acid on one end and a mRNA codon on the other (Figure 7). Obtain your three tRNA models and notice that each has three nitrogen base bonding sites. These three sites make up an anticodon, which complements a codon on the messenger RNA.
2. Build your anticodons b placing the following groups of three nitrogen bases on the tRNA models: cytosine, uracil, and adenine (CUA); cytosine, guanine, and guanine (CGG) and; and adenine, uracil, and guanine (AUG). H. Translation 1. Attach the anticodons to their complementary codons using the hyrdogen bond connectors. Again, guanine and cytosine must partener, while adenine and uracil partener. The tRNAs are now ready to receive amino acids. Bond each amino acid to its respective tRNA. Notice that the amino acid sequence has ben determined by how the anticodons were arganized. 1. Complete the synthesis of this portions of a protein by bonding the amino acid models together using the white bonding tubes. (See Figure 6 for comparison).
Each type of amino acid is carried to the ribosome by a particular form of tRNA, carrying an anticodon that forms a temporary bond with one of the codons in the mRNA. As shown above, the ribosom moves along the mRNA chain and “Read off� the codons in sequence.
Christopher Long Biology I Mr. Snyder November 13th, 2008
Assessment 1. Define the Following terms: !
Anticodon: a sequence of three nucleotides located on tRNA that complements a corresponding mRNA codon
!
Codon: a three-base sequence located on mRNA that determines which amino acids will be created during protein synthesis.
!
Nucleotide: the basic building block of DNA and RNA, which is composed of a sugar, a phosphate group, and a nitrogen base, which is always adenine guanine cytosine thymine or uracil.
!
Ribosome: an organelle found within the cytosol of a cell, which binds to the mRNA and facilitates the making of proteins.
!
Transcription: the process by which mRNA is constructed from a DNA template.
!
Translation: the process in which mRNA attaches to a ribosome for protein synthesis.
2. Draw a diagram of your DNA molecule. Keep the illustration in a straight “ladder� form as seen in Figure 2; do not attempt to draw the double helix shape. Specifically identify each nitrogen base. !
3. A partial strand of DNA has the nitrogen base pattern shown below. Indicate what nitrogen bases would be needed for a mRNA to complement this strand. !
4. What would be the nitrogen base pattern for the anticodons (tRNAs) that would bond to the mRNA strand in Question 3. !
5. How can protein be synthesized in the cytoplasm of a cell when DNA is contained in the nucleus? !
The genetic information contained in DNA is transcribed into mRNA, which goes into the cytosol for translation.
6. Complete the following Chart !
7. Using a venn diagram, compare and contrast codons to anticodons. Similarities and differences can relate to structure, components, and/or function. !
8. Read the following statement and write if each one is true or false. If you believe the statement is false, explain the reason why below it. !
“Uracil is always paired with adenine in double-stranded DNA.” !
!
“The process in which a ribosome controls protein synthesis is called transcription.” !
!
False. Thymine is always paired with adenine in double strand DNA.
False. This process is named translation.
“Adenine and guanine are purines; cytosine and thymine are pyrimidines.” !
True
!
“Protein Synthesis occurs within the nucleus of a cell.” !
!
False. Protein synthesis occurs in the cytosol of a cell.
“Nucleotides contain a sugar, an organic nitrogen base, and a phosphate group.” !
True
9. The DNA model you constructed was nine base pairs long and yielded three amino acid protein. Actual human DNA is billions of base pairs in length and codes for the production of millions of proteins. Some sequences are so specific that a change in a single base (termed an SNP, or single nucleotide polymorphism) can result in an entirely new protein structure. Research an example of an SNP and explain the effects it may have. !
One example of an SNP occurs in the blood disease Sickle Cell Anemia. In this hereditary condition, the protein Hemoglobin is mangled as the result of an SNP which occurs when thymine is substituted for adenine in the three nucleotide sequence which produces the amino acid glutamine. As a result, the amino acid valine replaces the amino acid glutamine — which deforms the Hemoglobin protein so badly that the entire red blood cell is affected, twisting, clotting, and eventually crystalizing. The combined affects of this disease result in a drastic shortening of the subject's life.
Christopher Long Biology I Mr. Snyder November 25th, 2008
Classification Lab What you need per group: ! Eight critter cards ! Key to the Kingdoms of Life ! key to each of the six kingdoms (Archaebacteria, Eubacteria, Protista, Fungi, Plantae, Animalia) ! Critter Characteristic Sheets (one for each kingdom) A Closer Look at Critter Cards: Take a moment to familiarize yourself with the information contained on each critter card. !
1. Review each of your group's “critters” and determine to which of the six kingdoms they belong. Use the information provided on the Critter Card, the information in the key booklet and the Key to the Kingdoms of life to make this decision. Record the “organism number” and scientific name(s) in the left–hand column on the appropriate sheet for each critter. Share your findings with your teacher before proceeding. 2. Become familiar with using a dichotomous or two–answer key. !
Using a Dichotomous Key: A “dichotomous” or “two answer” key allow you to compare two choices for each of an organism's characteristics. You should be able to read the pair of characteristics, and after examining you organism, you'll answer “no” to one pair and “yes” to the other. Then, using the line for “yes” characteristics, follow the instructions on where to go next in the key. If the characteristic you said “yes” to ends at the name instead of the directions to the next step, you've finished keying out the organism! The name at the end of the line is the group to which your organism belongs.;
To get some practice using the dichotomous key, lets identify this unique organism: !
Begin at 1a: 1a Organism shaped like a cube or a sphere If yes………….………....…..…………Go to 1a If no………….………....…..………….Go to 1b 1b Organism shaped like a cylinder If yes, the organism is………….Cylinderous cellous If no………….………....…..…………Go to 2A 2A Organism is a cube If yes, the organism is…………Cubous cellous If no………….………....…..…………Go to 2B 2B organism is a square………….……Squarous cellous
Based on the characteristics of its cubes shape, this “organisms would be identified as a “cubed cell” or “Cubous cellous.” A word of caution when using a dichotomous key –if you get to a point in the key where you think the answer to both statements in a pair is “no”— you probably made a mistake at an earlier step. Go back and give it another try. You should always be able to say “yes” to one of the two statement in each pair. 3. Identify the phylum to which a particular critter belongs by following the key until it ends in a phylum name:
4. Write down the group characteristic(s) that identify the phylum on the Critter Characteristic Sheet that matches the kingdom to which the critter belongs. For example: !
This Critter belongs to the Kingdom Animalia (Eumetazoa) and the phylum Arthropoda. It has these groups of characteristics: !
5. In the animal key, subphylum groups are also identified. If when keying out your critter you encounter a subphylum group, draw a line below the phylum characteristics and write down the subphylum characteristics below it. For example : !
6. In the Kingdom Eubacteria, Kingdom Plantae, and Kingdom Animalia (Eumetazoa) key class group are also identified in tables. Search the table for the matching class group under a phylum or subphylum group name. For example : !
7. Your teacher will check your group's summaries of the phylum andor class characteristics of each assigned critter.
1. How many cell types are present in your group's set of critters? !
Two cell types; Prokaryotes and Eukaryotes.
2. How many types of body organization, or body plan, are represented in yor group's set of critters? !
Two; unicellular and multicellular.
3. Which kingdoms represented in your set of critters produce young through sexual reproduction? !
Animalia, Plantae, Protista, and Fungi.
4. In which kingdoms do critters represented in your group's set reproduce from only one cell or parent (i.e asexual reproduction)? !
Eubacteria and Archaebacteria.
5. Give an example of asexual reproduction in a common food plant. !
The bud of a potato is an example of sexual reproduction in a common food plant.
6. Which life characteristics are present only in Eubacteria and Archaebacteria? !
Cells without nuclei
7. What are different ways in which two organism can get energy? !
Photosynthesis, chemicals, ingestion, and absorption
Christopher Long Biology I Mr. Snyder December 20th, 2008
Natural Selection Lab Determine how natural selection acts on the color and size of a moth. Materials you will need: ! ! ! !
An environmental tray with a dark interior. An environmental tray with a light interior. One set of moths with nine varying intensities One set of various sized squares
1. Find a partner, and unpack two boxes, your squares, and your moths. Put the squares in the lighter box, and the moths in the darker box. There should be two people in each group, and all materials should be set up. 2. The members of each groups should take turns with each other, removing five squares at random, recording their size, and replacing them in the box. Once this is finished, they should do likewise with their moths. 3. The groups should then switch boxes, and perform the steps in #2 to the new boxes. Once a groups has recorded information from three boxes, they may cease working. Data: 1. The selection of moths with various intensities. White Number Selected
3
Total Class Count
25
Grey 4
2
2
59 16 14
Black
0
0
0
1
4
26
9
7
27
41
2. The selection of squares with various sizes. 1/2
3/4
Number Selected
5
0
Total Class Count
32
1
1
5/4
6/4
7/4
2
0
0
3
4
1
2
53
10
3 100
Study Questions: 1. If the rows of colored moths or different size squares are arranged in a single file from white to black or small to large, is there an equal number of object on either side of the middle object? !
Yes
2. Looking at the class data for which colored moths were selected, did the class select more lighter colored moths or more darker colored moths? !
More darker colored moths
3. How would you explain the class results? !
Lighter colored moths stand out more in the experimental environment chosen.
4. Looking at the class data for which different sized squares were selected, did the class select more smaller–sized squares or more larger–sized squares? !
More smaller sized squares.
5. How do you explain the class results? !
Experimental error.
6. Imagine that most of the trees in a forest of over 100 years ago had bark that was light in color. In addition, some of the birds in this forest fed on moths. What kind of moth would be eaten by birds more frequently? Explain why. !
Moths with darker colors, because they stand out.
7. If uneaten moths mated, what color offspring would tend to have a few more of? !
Lighter colored offspring.
8. Further imagine that after a number of years, the nearby city became more and more industrialized. Smoke poured out of the chimneys and settled on the tree trunks. What happened to the color of the tree trunks as time progressed? !
The trunks darkened.
9. What kind of moth would be eaten by the birds more frequently? Explain why. !
Lighter窶田olored moths, because they stand out more against the environment.
10. If uneaten moths mated, what color offspring would tend to have a few more of? !
Darker colored offspring.
11. As the years continued the trees became darker and darker. If the surviving moths of each generation were to continue to mate, what do you think in time would happen to the entire population? !
Lighter窶田olored moths would die out, and the entire population would become dark.
12. You might say the moths evolved from one color to another. What caused the change to take place? !
Environmental change occurred
13. To summarize, you have learned that individuals differ. Because of these differences, some will have a better chance of surviving. What differences give some individuals a better chance of survival? !
Traits better suited for an organism to survive in its environment.
14. It should be pointed out that there may be many differences that help an organism survive. A more favorable structure is not the only reason. Those that survive live to give birth to young that are more similar to the parents. This idea was observed, studied, and proposed, by Charles Darwin. He called it the Theory of Natural Selection. Some people also call it survival of the fittest. According to Darwin, what was nature selecting? !
Genes more favorable to an organism's survival.
15. The giraffe survives by eating leaves off of trees. The giraffe did not get its long neck by stretching its neck to reach taller and taller leaves. (as proposed by Lamarck). Using Darwin's theory, how would you explain how the giraffe got its long neck? !
A long neck is more conducive to the survival or giraffes. Thus, organisms with genes for this trait had a greater chance of survival, and gave birth to more live young.
16. In summary, according to Darwin, what kind of an individual survives? !
The individual most adapted to its environment.
17. Is the case of the peppered moth an example of microevolution or macroevolution? Explain. How could this example be used to illustrate macroevolution? !
Microevolution, because only color is changed. Furthermore, if steps occur on small scale, there is no reason why they cannot occur on large scale.
Christopher Long
The Clam Kingdom: Animalia Phylum: Mollusca Class: Bivalva Genus: Mya Species: Arenaria
I. Purpose: The purpose is to examine the clam internally and externally by dissection. II. Materials: 1. 2. 3. 4. 5. 6. 7.
Dissection tray Clam Dissecting Needle Dissecting Probe Scissors Forceps Scalpel
III. Methods: A. External: The dissector carefully looked over the clam, noting the tannish white color of it's dual sided shell, and the small growth lines on the surface, a long distance between which indicated that his clam had experienced an extended period of growth, before his eyes moved on to the white umbo, oldest part of the exterior, which appeared on either side of the shell. He turned the shell so that the umbo was to his left, and the opening of the clam was to his right. He then identified the anterior, which was pointier and longer than the posterior, which he identified by it's rounded end shape, and closeness to the umbo. As he touched the clam, he noted the rough texture of the exterior, and it's hard, rock-like surface. Next he identified the dorsal side of the animal, which judging from the location of the umbos, the anterior and the posterior, was the side he was looking at. He briefly turned the clam over, to look on the ventral side, and after he realized that the coloration was lighter, flipped the clam back to it's original position, and examined the hinges and ligament of the clam, nestled all along the space between the umbos, which were extremely dark, and green colored. Their texture was smooth, but felt a little scraggly. Nothing more was observable to him, so he sat the shell down, and prepared to examine the interior. B. Internal: The dissector dissector easily pried open his clam, whose adductor muscles were not strong enough to make a scalpel necessary. He carefully opened the shell, without affecting the clam, and examined the pearly layer of the shell, which was white in color, somewhat soft, and much smoother than the horny layer he had observed on the outside. He then cracked off a piece of the shell, so that he could observe e prismatic layer within, which was thicker than the pearly layer or the horny layer, and between the two in coloration. After he finished, the dissector removed the clam from it's hold on the other half of the shell, and examined both sides. All it's organs were covered entirely by the mantel, a dark-brown, smooth–textured material which excreted shell, and had been attached to the shell at the edges, before he detached it. The dissector, who desired to see past it, carefully detached the mantle from all organs on the clam's body, using a scalpel, and assorted tools. When he did so, a torrent of aqueous, pearly colored hemocoel, used in the animal's circulatory system, poured out of the shell. Next, the dissector examined the clam, and noted the major organs. Immediately, he examined the adductor muscles, located at each end of the clam, which looked like raspberry textured, dark pink circles, the anterior of which was slightly larger, and more circular than the posterior. He then began to inspect the clam's pair of gills, located at the ventral, and centered evenly between the the anterior and posterior. They were each slightly larger than an umbo, and hued a light yellow-brown. The ridges on their surface, used to increase to area for gas exchange were clearly visible, each consisting of several flaps of tissue. Alongside and slightly posterior to the them, the dissector could see the incurrent siphon, used to ingest water and small animals, located ventral to the gills, and the excurrent siphon, used for waste removal, located dorsal too them. Both siphons had a ridgy texture, and were black in color. The dissector then carefully removed the gills with a scalpel, and examined the visceral mass, murky green colored and smooth, that were attached to the shell primarily by the foot, which fit neatly into the shell. At the posterior of the clam, the dissector could see a small, red-colored mouth, well protected by two palps of the visceral mass's color, and to the anterior, he could see the anus, a small opening of darker color, but no different texture. Posterior this ran the rectum, of the visceral mass's color and texture. The dissector then extracted the foot from the shell and observed the black-lined hole through which it fit. At last the dissector sliced the visceral mass in half with a scalpel. Inside, he could see the translucent,
white-colored intestine, which connected to the stomach, and ran throughout the visceral mass, and the remains of the stomach, that was interior and connected to the mouth, and whose color and texture was unobservable. The dissector could not find observe the coelom, heart, nephridophore, gerital pore, or any of the ganglions, as they were to small, or destroyed in dissection. The dissector, after not locating these, found the gonads, which were green in color, and mushy in texture, distributed throughout the interior of the visceral mass. Finally, he located the digestive particles, located throughout the visceral mass, of mushy texture, and pale coloration.
IV. Observations: A. External Anatomy of a Clam
IV. Observations: A. External Anatomy of a Clam
V. Conclusions: 1. Why are clams called Bivalves? Clams are called Bivalved because their shell is divided into two halve divided by a valve 2. What is the function of the mantle? The function of the mantle is to secrete the clam's shell, and protect the visceral mass. The mantle also secretes nacre. 3. Describe the path of water through a clam. Water enters a clam through the incurrent siphon, and then proceeds to minute openings (or ostia) which line the gills. Lamellae (the many folds and ridges which make up the gills) eventually lead to the cloacal chamber, that empties out throughout the excurrent siphon. 4. Describe the filter-feeding process of a clam. The surface of the gills, mantle, and visceral mass are lined with cilia that beat in a coordinated manner. This movement causes water to enter the mantle cavity through the incurrent siphon. Along with water, zooplankton, phytoplankton, and organic detritus are carried into the mantel cavity. As the continuous stream of water passes along and through the gills, food particles become entrapped in the mucus that lines the surface of the gills. The food laden mucus is driven to the labial palps where the indigestible mater is separated and the food carried off to the mouth. The rejected material is moved to the mantle edge of the clam shell and expelled out the clam. 5. Which organs play a part in the digestive process of a clam? (answers in bold below) Food ingested through the mouth passes into the stomach. Here the food is broken up into fine particles and mixed with a digestive enzyme. This is accomplished by the rod-like organ within the stomach called the crystalline style. Digestible food particles are swept into the digestive gland that surrounds the stomach. Indigestible food particles are swept into the intestine. 6. Describe how clams reproduce. Generally, when clams reproduce, eggs are lodged in the gills while sperm is released into the surrounding waters via the excurrent siphon. Water carrying sperm passes through the gills and fertilizes the eggs. Early embryonic growth occurs here. When embryos are large enough they are passed on to develop independently of the parent. 7. Describe the nervous system of a clam. Clam's have three pairs of connected ganglia, each pair of which is a source of nerve fibers that lead to adjacent organs. There is also a pair of minute sense organs which detect changes in equilibrium called statocysts, located posterior to the pedal ganglions. 8. Describe how a clam uses its foot to move. In order to move, the clam extends it's foot, and then expands it, to form and anchor. Then, the clam allows it's body to move forward, pulled by the extended foot. The clam then retracts its foot, or continues to move. 9. Describe the development of the freshwater clam. The fertilized eggs of the clam develop within the gills of the female and become larval clams known as glochidium. The larval clams superficially resemble their parents with two chitinous halves joined by a hinge. These halves are held together in an open position by a single adductor muscle. The open end of the valved have teeth which are hook shaped. When the glochidium reach a particular size they are expelled by the parent into the surrounding waters. Here the larva either sink to the bottom or become suspended in the water. In either case the glochidia remain with their valves gaping waiting for a fish to brush against them. The larva are sensitive to their fish host and clamp tightly onto any superficial fish tissues they touch. If the larva do not attach themselves to a host
within a few days of leaving their parents they die. When the glochidia is attached to a fish the tissues of the the fish soon grow around it. During this encystment the larva undergoes marked changes and the adult organs are formed. After a period of 10 to 30 days the young clam breaks free of its host, falls to the bottom and begins the juvenile phase of its existence. The juvenile phase lasts until the clam becomes sexually mature in one to eight years. 10. Briefly summarize your experience your experience in one paragraph. My experience of this dissection was as good as I think any dissection could be, and although I admittedly dislike dissecting in general, everything went very well. The only way it could have been a better was if the clam was much larger, and all the organs were visible. Before the dissection began, I was worried that it would feel like I was dissecting a mammal, but once it started, I felt more as if I were taking apart a rubber toy, laced with water. I can't really say whether that's a good thing or not, but it certainly is strange. Ultimately, despite perfect instructorial care, I can't say I look forward to the next one— and I hope that I never have to dissect a creature who's flesh looks human, but I can say this: I experienced a pleasant thrill from using an instrument so precise as the scalpel, and I am glad to have had the experience.
Christopher Long
The Earthworm Kingdom: Animalia Phylum: Annelida Class: Oligochaeta Genus: Lumbricus Species: terrestris
I. Purpose: The purpose is to examine the Earthworm internally and externally by dissection. II. Materials: 1. 2. 3. 4. 5. 6. 7. 8.
Dissection tray Earthworm Dissecting Needle Dissecting Probe Scissors Pins Forceps Scalpel
III. Methods: A. External: The dissector began by measuring the worm, which he determined to 25 cm, and estimated the worm to be about 130 segments long, he performed a general bodily analysis of the worm. First, he located the clitellum, a smooth-textured light pink organ, located about 5 cm from one end of the earthworm, which he then determined to be the worm's anterior. He used his dissecting probe to briefly analyze the mouth, a small opening at the anterior, before he examined the anterior parts of the worm as a whole. He noticed that the anterior end of the worm was somewhat conic in shape, by comparison with the posterior, that was slightly flattened, and that the coloration tapered from dark brown on the anterior, to medium-grey at the posterior, where the anus, a small opening at the anterior was located. He then examined the anus of the worm with his dissection probe, and began to perform a general analysis of the the worm's dorsal side. The worm was segmented, and the texture was bumpy, however the animal was covered in a thin, translucent cuticle, which secreted mucus to protect the worm. With his dissection needle, the dissector scraped a small part of the cuticle on the worm, and observed it, before he noted the dorsal blood vessel, which ran underneath the worm's skin from the top to bottom, along it's center. The dissector than turned the worm over, and examined it's ventral side, which was sicklywhite, and slightly flatter than the skin of the front. About 15 segments down the worm, he could see two small sperm vents, at running diagonally into the worm's body, that were used in reproduction. Next the dissector brushed his finger over the edges of the worm, and felt something bristly, that he reasoned to be the setae. Having nothing further to observe, the dissector turned the worm over, and prepared to begin his dissection. B. Internal: The dissector began by placing one of his pins into the dorsal-posterior of the worm, and then placing the other three segments from the anterior of the worm. Next, he counted five segments down from the clitellum, and placed a final pin. After the dissector fasted the worm to the dissection tray, he proceeded to make an incision with his scissors, starting at the segment immediately behind the clitellum, and passing through to the segment three from the anterior. He could observe a small amount of translucent, puseous-white colored body fluid, but not enough to hinder his observations. The dissector observed that the integument was still attached to the worm's body by small septa on the interior of the worm's body. The dissector held the sides of the earthworm apart with his forceps, while he used his dissection needle to sever the septa from the integument. The dissector then pinned the earthworm's integument to his dissection tray, observing that its interior was pale white, and began to observe the earthworm's coelom, starting at the posterior most part he had dissected, the intestine, a protracted organ that was blackish in coloration, and bumpy in texture. Using his scalpel, the dissector made an incision along the length of the intestine, and carefully observed the interior. He could see the intestine's black typhlosole, responsible for augmenting digestion, which was normally held aloft in the intestine, as well as green food particles undergoing the process of digestion. Anterior to this the dissector observed the gizzard, which was much harder and larger than the intestine, and colored lighter grey, and the crop, which was slightly smaller than the gizzard, softer than it, and located anterior to it, but otherwise shared the same traits. To the anterior of this, the dissector observed both the large, tubular, seminal vesicles, and the smaller, less elongated, dot like seminal receptacles. Both sets of organs were smooth, white, and located dorsally of the five, circular, black aortic arches, which the dissector moved the reproductive organs aside with his dissection needle to see. Located underneath these, the dissector saw the tubular, grey colored esophagus, which connected the crop to the pharynx, a grey, muscular organ responsible–
for sucking earth into the worm's body through the mouth, to which it connected. The dissector then examined the dorsal blood vessel, a small, black tube which ran the worms length, over the dorsal side of the organism. It was connected by the aortic arches to the ventral blood vessel, an organ on the ventral side of the organism, which the dissector analyzed immediately thereafter, and found to have the same properties. After he examined both the ventral and dorsal blood vessels, the dissector examined the worms nervous system. The dissector first observed the very small, white, ventral nerve cord, which ran the length of the worm, that the dissector observed to be connected to the integument. The dissector followed the nerve cord this to the anterior end of the organism, where, in the top two segments, it suddenly expanded, ventral to the mouth, and formed the cerebrial ganglion, which was white in color, bumpy and texture, and extremly small. Finally, the dissector located the slits he had seen on the interior, called spermal vents, ventral to the clitellum. The dissector then ended the dissection, as there was nothing left to examine.
IV. Observations: A. External Anatomy of an Earthworm
IV. Observations: B. Internal Anatomy of an Earthworm
V. Conclusions: 1. List the characteristics shared by all annelids. The characteristics shared by all annelids are that they have a body divided into segments or metamers know as somites, display well developed cephalization (sense organs concentrated at anterior or “head” end, an elongated body, and a closed circulatory system with hemoglbin and amebocytes. 2. What is the function of Setae? Setae are briscles located on the ventral side of the body which are asscociated with muscles that can push them out or retract them, and aid in providing traction for locomotion. 3. What is another name for the body segments of an earthworm? Another name for the body segments of an earthworm is metemeres. 4. What is the function of the Clitellum? The clitellum is a glandular organ that produces mucus for copulation and secretes the cocoon into which the eggs are deposited. Eggs emerge from paired oviducts, small opening on the ventral surface of somite 14. Sperm ducts are on somite 15. 5. How many hearts does an earthworm have? There are five pairs hearts, named aortic Arches, located around the esophagus from segments 7 to 11. These arches pump blood throughout the worm in a closed circulatory system consisting of the large dorsal and ventral blood vessels, connecting vessels and capillaries. 6. Describe the process of digestion in an earthworm? Food is taken in through the posterior of an earthworm, at the mouth, sucked in by the muscular pharynx, and then transported a short time along the esophagus, until it reaches the crop, a thin walled swelling in which food is stored temporarily before entering the gizzard. After this, the organ enters the gizzard, a muscular organ that uses particles of soil to help grind up food for digestion, and then passes into the intestine, a long tube where food is digested, and nutrients absorbed. Finally, indigestible matter is excreated from the posterior of the animal through the anus. 7. What is the function of the typhlosole? The typhlosole is a ridge or fold hanging inside the intestine from the dorsal side. It enlarges the surface area of the intestine which increases the efficiency in absorbing food. 8. What is the term given for the slowing down of an earthworm's bodily functions? Soil moisture is an important factor in determining good earthworms habitat. Earthworms have no respiratory organs. They obtain oxygen by diffusion through their moist skin. When the skin dries, oxygen cannot diffuse into the worm, causing death. Earthworms have adapted to survive moderately dry soil periods by slowing down their body functions in a period know as diapuse. As much as 70% of the worm's body fluid may be lost during this period before it dies. If the worm survies the dry period, it can quickly reabsorb water and resume activity. 9. Distinguish the different families of class oligochaeta. The members of the family Aeolosomatidae are microscopic oligochates which are exclusively fresh water worms. They reproducer aesexualy and feed on algae. The family Tubificidae contains the tubifext worms (sometimes called “bloodworms due to their bright red pigmentation”) that are popular as fish food. These fresh water worms can be seen on the muddy bottoms of ponds and streams and occur in large wiggling clumps. Tubifex worm wave their cranial ends back and forth collecting floating–
detritus which is then ingested. The family Enchytraeidae includes both aquatic and terrestrial species. They are up to 25mm long, and are whitish in appearance. The relatively common Enchytraeus albidus live under debris along the seashore. 10. Summarize your dissection experience in one paragraph. My dissection was remarkably successful, and far easier than that previous, yet at the same time, had a larger disgust factor. On the one hand, all of the internal organs were easy to locate, and I could observe the body process's of the worm with great detail (including setae, which were intriguing to the touch), and the body layout was clear, but on the other side, I found the similarities between myself, and this fellow terrestrial organism to be disturbing, especially in the layout of their digestive tracts, which followed a plan very close to our own. Ironic, I suppose, considering that mollusks are closer to us. With exception of a slight setback in time, and a few small slips of the dissection needle, everything else was alright, and in the end I certainly have no right to complain. Things went well.
Christopher Long
The Crayfish Kingdom: Animalia Phylum: Arthropoda Class: Crustacea Genus: Cambarus Species: s.p
I. Purpose: The purpose is to examine the clam internally and externally by dissection. II. Materials: 1. 2. 3. 4. 5. 6. 7.
Dissection tray Crayfish Dissecting Needle Dissecting Probe Scissors Forceps Scalpel
III. Methods: A. External: The dissector began his observations by measuring the length of his crayfish, and found it to be approximately 8 in. long, from the anterior to the posterior. He then flipped the crayfish to its ventral side, without making observations, and used his dissecting probe to probe the crayfish's anus, located at the posterior-most segment, called the telson, before flipping the crayfish once more, so that the dorsal side faced upwards. The dissector then examined at the segmented exterior of the crayfish, which was smooth, pink, shiny, and hard to the touch, but slightly flexible, and covered in small, translucent,sharp hairs, especially the edges of appendages. Located at the exterior of the organism was the largest segment, known as the carapace, that covered the entire cephalothorax of the crayfish, and at the animals anterior, spiked sharply, to form the conical rostrum. The carapace was dived by the line of fusion between the head and the thorax, and indention known as the survical groove. The dissector used his dissecting probe to carefully lift the side of the carapace, and observe the feathery, translucent gills, which it protected. Posterior to the carapace, the dissector observed the seven segments which composed the abdomen of the crayfish, five of which were similar to each other in appearance, but decreasing in size, followed by by one smaller, flatter segment, to which was attached the telson, which was paddle-like. Branching from the segment anterior to the telson were two pairs of uropods, shaped like the heads of a canoe paddle, that extended to either side of the telson, which he found spreadable. Both the telson and the uropods were extremely bristly. The dissector then turned to the anterior most part of the crayfish, and examined the long, segmented black antennae, which were rough to the touch, and rested below the rostrum, to either side. In between these, he could also see small appendages known as antennules, that were much thinner and shorter than the antenna, colored red, and smooth. Above both these pairs of appendages, immediately underneath, and to either side of the rostrum, the dissector could see two black, compound eyes, that rested on movable eyestalks. Next, the dissector observed the celipeds of the crayfish, that were thick, slightly rough appendages with approximately five joints, and extended horizontally in front of the organism. They were of white coloration on the ventral side, and ended in large pincers called celae at the anterior, which the dissector subsequently removed for measurement, and found to be about 1.5 inches in length, before he opened and closed them, noting that they were very inflexible, and covered in sensory hairs. The dissector proceeded to examine the four pairs of walking legs, located posterior to the chelipeds, that were much smaller, moderately shorter, and considerably more flexible then them, due to the presence of a varying number of additional joints, but like the chelipeds were white on the ventral side, and pink on the dorsal side. The first pair of walking legs ended in tiny claws, used to hold on to grasp small objects and the others were spike-tipped. All the crayfish's joints were translucent white in color. Next, because the dissector had fully observed the dorsal side, he turned the crayfish to its posterior, and began an examination of the swimmerets; five pairs of small, leg-like appendages connected to the underside of the first five abdominal segments, which due to being tucked in, indicated that the crayfish was a female. The dissector removed the swimmerets with his forceps, and observed that the underside of the abdominal sections was a stained, murky translucent color, and rubbery in texture, that rose in ridges in those areas where two segments met, and vanished into the cephalothorax. Through it, he could make out the thin, black, ventral nerve chord. The dissector then examined the posterior section of the cephalothorax, where the walking legs and chelipeds were attached to the body by large, gray, joints. It was of harder texture, and had a slightly varied, murky color. The dissector pulled both the legs, and the chelipeds from the cephalothorax with his forceps, and then moved to the anterior of the cephalothorax, directly posterior to the mouth, which he probed using his dissection probe. Here, the dissector could observe several pairs of maxillipeds, and examined them in turn. The dissector first examined the longest pair,
which bore a resemblance to the walking legs, possessing a pinkish color, much increased length, and a hard, jointed exterior, before he removed them with his forceps, and examined the second pair of maxillipeds, that were small, smooth, white, and of similar size and texture to the antennules. After removing them with his forceps, the dissector examined the final pair, which was similar to the second but slightly smaller, and removed them with his forceps. Now the dissector could see clearly see the small, murky colored, feathery appendages, of the maxillae, that were located on the head section of the crayfish, and covered the mouth. He removed them with his forceps, and finally, observed the pair of white, plaque stained mandibles, located on the lower jaw of the crayfish, each about the size of a human tooth. The dissector then prepared to examine the interior of the crayfish. B. Internal: The dissector the dissection by making a small incision with his scissors alongside the lower side of the sixth abdominal segment, about 1 cm from the gill line, and continuing to cut along this path until he was within 1 cm of the eye, before cutting horizontally to the other side, and then back the length of the crayfish. Once this was completed, the dissector carefully lifted the exoskeleton from both the cephalothorax and the abdomen, before using his scissors to remove the telson. The dissector then began his inspection of the interior, starting at the posterior. The dissector first observed the intestine, a thin, black tube which traveled the visible length of the crayfish to the anus, and the white, semitransparent, rubbery tail muscle that surrounded it on either side. The dissector then recognized that a long, very thin white tube known as the dorsal abdominal traveled dorsal to the intestine, for the depth of the abdomen, and vanishing into the cephalothorax. The dissector next lifted the tail muscle with his gloved hand, in order to examine what lay ventral to it, and in the process penetrated a slight remnant of the epidermis, a thin layer of semitransparent tissue which had covered the entirety of the organism, until much of it separated from the interior, when the dissector removed the exoskeleton, which upon seeing the tissue, he briefly examined, and found clear of anything notable. The dissector then located a small, white, ventral nerve chord, which akin the dorsal abdominal, also ran the visible length of the organism. Because the dissector could not observe anything further in the abdomen, he turned his observations to the cephalothorax, and examined the organs there. Firstly, the dissector found a large concentration of small, tapioca-like, orange-colored eggs, which broke into pieces on contact with a dissection probe, but were moderately firm. The dissector allowed them to remain, and examined the sides of the crayfish, attached to which were many overlapping, feathery gills of translucent tan color, that had been connected directly to the crayfish's legs. Next, the dissector removed the eggs, and then examined what lay ventral to them; a small, red organ, which due its connection to the abdominal artery, he recognized as the heart. The dissector then moved the heart to one side with his dissection probe, and upon examination of what was ventral to it, located the crayfish's gray, soft digestive gland, which ran under the intestine, and split into two spiky, white testes near the organ's posterior. Located anterior to this, the dissector could see a black, bulging, and soft to the touch organ known as the stomach, which filled most of the remaining anterior, and was connected to the mouth by a small, similarly colored esophagus. The dissector carefully removed the stomach, and observed the interior surface of the cepholothorax's interiors anterior, which consisted of a few muscles running vertically, a small remnant of the epidermis, and to either side, the gills, which he had already observed. Anterior to this cavity space, the dissector examined the mandibular muscles, two pairs of light-purple muscle concentrations that felt extremely dense, and anterior to those, he probed the crayfish's green gland using his dissection probe, and found it to be felt relatively soft. Ironically, the dissector noted that the green gland was tinted yellow. Finally, the dissector followed the ventral nerve cord to the brain around the two circumoesophagial nerves. The dissector removed it, and observed that it was a small white sphere of rubbery tissue located slightly dorsal, and anterior to the green gland. The dissector the ended his dissection, as there was nothing else to examine.
IV. Observations: A. External Anatomy of a Crayfish
IV. Observations: B. Internal Anatomy of a Crayfish
V. Conclusions: 1. Identify at least four animals that belong in subphylum Crustacea. Four animals that belong to subphylum Crustacea are crayfish, lobsters, crabs, and shrimp. 2. Identify at least three distinguishing characteristics of subphylum Crustacea. Three distinguishing characteristics of subphylum Crustacea are bodies covered by a chitinous exoskeleton strengthened with calcium salts, two pairs of antennae, and a pair of maxillae and of mandibles. 3. What characteristics do Annelids share with Arthropods? Both Annelids and Arthropods are metamorphic (their bodies are segmented) although in some Arthropod groups such as ticks the metemerism is greatly reduced, both have a brain which is located cranially and dorsally but is followed by a ventral nerve chord with a ganglionic swelling in each segment, and lastly, primitive Arthropods show paired appendages which can be compared with the paired parapodia (or setae in the earthworm of each metamere in the Annelids.) 4. What distinguishing characteristics do Annelids share with Arthropods? Arthropods are characterized by having hard, protective body covering: the exoskeleton. Coinciding with the evolution of this skeleton, the muscles for movement had to change. The locomotory muscles evolved from a simple body musculature like that of the earthworm (composed only of longitudinal and radial muscles) to a complex series of specialized muscles to control the limbs and tail. The circulatory system has changed from the Annelid's closed type to an open circulatory system where the hemolymph (blood), is forced away from the heart in arteries, but flows back to the heart through open venous cavities or sinuses. The heart in Arthropods has evolved from the five dorsal aortic arches of the annelids to a single distinct dorsal heart. 5. Identify/describe all the mouthparts found in a crayfish. There are three pairs of small mouthparts originating from the the head (the mandibles and two pair of maxillae). There are three more sets of mouthparts originating from the head (the mandible and two pairs of maxillae). There are three more sets of mouthparts, the maxillipeds that arise from the thorax in the region nearest the mouth. These small appendages function as touch sensors and help to hold and manipulate food. 6. Identify the five major arteries found in a crayfish. What organs are supplied by those arteries? The five major arteries extending from the heart are the Opthamolic, Antennary, Dorsal Abdominal, Hepatic, and Sternal Arteries. The opthamolic artery aries from the medial portion of the cranial ends of the heart. It proceeds straight toward the head and supplies the head and esophagus. Arising from either side of the opthamolic artery and extending anteriorly to the green gland are the antennary arteries. These supply the stomach, green glands, antennae, and lateral portion of the head. The dorsal abdominal artery is a large artery extending causally from the heart. It supplies the intestine and the tail muscles. The hepatic arteries branch from the ventral surface of the heart and supply the hepatopancreas. The sternal artery extends from the ventral side to the ventral nerve chord where it branches. The anterior branch is the ventral thoracic artery and the caudal branch is the ventral abdominal artery. The ventral thoracic artery supplies the leg and the ventral abdominal artery supplies the tail muscles. All of the arteries divide into smaller vessels and capillaries, but the crayfish has no veins to return the hemolymph to the heart. Instead, the hemolymph is returned to the heart through a series of open sinuses. 7. Identify the habitats of a crayfish. Crayfish are found in freshwater ponds and streams all across the globe.
8. Identify the four genera of a crayfish. The are four genera of crayfish, Procambus, Orconectes, Cambarus, and Astacus. There are about 100 species in the United states, and probably around 300 species worldwide. In the United states, Procambus sp. are the most common west of the Rocky Mountains, Orconectes sp. and Cambarus sp. are the most common to the east, and Astacus sp. in the south 9. What do crayfish eat? The diet of crayfish consists of snails, tadpoles, insects, aquatic and terrestrial plants, and decaying organic matter. 10. Briefly summarize your experience in one paragraph. This dissection was probably the hardest one I've had so far, simply because of the quantity of information to parse, however I did manage to observe everything relevant to the dissection. It would have been interesting to look at the mouthparts with bit more detail, as I found them extremely interesting, however it was still a good (if not “pleasant”) experience to examine them in person. My general dislike of dissection now carries on only for invertebrates, and in particular, mammals, as I have come to find dissecting Crustaceans to be somewhat interesting, and in a diminished sense, enjoyable. From a technical view, the dissection went extremely well, and the only holdup was a slight delay in my recognition of the eggs. On a related note, several months back for my birthday I was served sushi mixed with a type of orange caviar, so when I noted the color of the crayfish's eggs, I was slightly amused. Obviously I didn't eat crayfish eggs, but it is strange what ends up in the stomach…
Christopher Long
The Starfish Kingdom: Animalia Phylum: Echinodermata Class: Asteroidea Genus: Asterias Species: s.p
I. Purpose: The purpose is to examine the Starfish internally and externally by dissection. II. Materials: 1. 2. 3. 4. 5. 6.
Dissection tray Crayfish Scissors Dissecting Probe Dissecting Needle Forceps
III. Internal and and External Anatomy of a Starfish:
IV. Conclusions: 1. In what ways are Starfish unique to other invertebrates you have studied so far? Starfish are unique among the vertebrates I have studied thus far (clams, earthworms, crayfish) in that Starfish and other Echinoderms are Deuterostomes as opposed to being Protostomes. 2. What are the major differences between protostomes and deuterostomes? In protostomes, segmentation is complete, the brain is located above the gut, while the nerve chord is below the gut, a mesodermal skeleton is never present, embryonic cleavage is determinite, and the blastoplore becomes the mouth. In deuterostomes, segmentation is incomplete, both the brain and the nerve chord are above the gut, a mesodermal skeleton is often present, embryonic cleavage is indeterminate, and the gastropore becomes the anus while the “second mouth� forms as a new opening. 3. Where do all Echinoderms live? The phylum Echinodermata is composed of many familiar marine animals and is distinguished by pentamerous radial symmetry, a calcareous dermal endoskeleton with projecting spines, and also a system of coelomic canals and tube feet (the water vascular system) that is used in slow locomotion and manipulation of the food. 4. Identify five classes of Echinoderms; give an example of an animal that belongs to each class. Echinoderms consist of two subphyla, the Pelmatozoa and the Eleutherozoa. The primitive Pelmatozoa contains one class, the Crinoidea (sea lilies). The Eleutherozoa contains four classes, the Ophiuroidea (brittle stars), the Holothuroidea (sea cucumbers), the Echinoidea (sea urchins and sand dollars), and the Asteroidea (starfish). 5. How many species of Starfish are there? About 1700 species of starfish have been described, living in marine coastal waters from the north to the south poles. 6. Identify at least four external characteristics of a starfish. The opening of the water-vascular system, the madreporite, is a large button-like structure that is located off center on the disc between two arms. The inconspicuous anus is in the center of the disk, and both structures are located on the upper, aboral surface of the starfish. The mouth is in the center of the underside, or oral surface of the starfish's anatomy. On the oral surface of each arm are open ambulacral grooves extending from the mouth to the tip of each arm. These deep furrows contain two or four rows of tube feet, podia, with protruding suckers; features unique to the echinoderms. 7. Describe the process of water movement through a starfish's water vascular system. Water enters the system through the sieve-like madreporite in the aboral surface and passes through the stone canal into the ring canal which encircles the mouth. Nine sacs, Tiedemann's bodies, are located on the inner edges of the ring canal. These sacs are the breeding grounds of amoeboid cells that are found in the fluid of the water-vascular system. Extending out from the ring canal are five radial canals, one into each arm, through which water then travels. At regular intervals water passes into lateral canals, which branch off the radial canal and lead to ampulla, which are muscular bulbs located along both sides of the ambulacral ossicles. When the ampulla contract, water is forced into the tube feet, extending them, and enabling them to attache to substratum with their suckers. Excess water is excreted from the body of the starfish via the anus.
8. Identify the digestive organs of a starfish. Just under the dorsal endoskeleton are located large paired organs, hepatic ceca. There are a pair in each arm and they function as secretory glans to aid digestion which involves aversion of the stomach and external digestion. There is a connection between the hepatic ceca and the disk, the hepatic ducts, which all secrete into the small aboral pyloric stomach. Dorsal, or above the pyloric stomach is a small pair of lobed rectal ceca, which function in waste consolidation before excretion through the hard to see anus. Underneath, or ventral to the pyloric stomach is the large, bag-like cardiac stomach, which protrudes through the mouth while feeding. The everted stomach engulfs the prey and can insert itself into a slit in a shellfish only 0.1 mm wide. Digestion can begin outside the body until the cardiac stomach is retracted by five pairs of retractor muscles, one in each arm. 9. Describe the skeleton of a starfish. The aboral surface of the starfish is an arrangement of calcareous plate or ossicles of endoskeleton that allow both lateral, and up and down movement. Numerous spines portrude from the surface of the endoskeleton and give the body a spiny appearance, hence the name echinoderm— spiny skin. Small, moveable spines are covered by a thin layer of epidermis. The inner pattern of a starfish's endoskeletal framework is also composed of ossicles. The largest ossicles, ambulacral ossicles, support the ambulacral groove, and provide attachement for the tube feet. 10. Briefly summarize your experience in one paragraph. I began my dissection in the mistaken belief it wouldn't be quite so easy as the dissection guide portrayed, but upon starting, carried out the dissection in total leisure, and later, jokingly questioned whether I had perpetrated one at all. Rather than the carefull distinctions, and delicate machinery of a crayfish, I found clearly distinct, and almost brutally obvious internal organs, which easily detached from each other. The water vascular system in particular proved much easier to distinguish than I'd thought; within a few seconds, I located the stone canal, perhaps the starfish's least distinguishable part. After the dissection proper concluded, I did run into one difficulty, but I easily re-did my defective slide, and upon examination, discovered the gender of my starfish. (Eggs!) The smell, which affected some immediately, only irritated me while I cleaned my tray, but came on strong. Thank heaven for allergies! Without them, I probably would have seen the previous day's food. In any event, it was a good dissection— so good, in fact, it leaves me a bit wary about the next one.
Christopher Long Biology I Mr. Snyder Feb. 25, 2009
Analysis and Conclusion Questions: 1. What characteristics are shared by all vertebrates? !
All vertebrates posses vertebrae, bones or cartilage that surround and protect the dorsal nerve chord and form the spine, a cranium, which protects the brain, and an endoskeleton composed of bone or cartilage.
2. What key characteristics separate classes Osteichthyes and Chondrichthyes? !
Member of class Chondrichthyes posses jaws and fins, but their skeletons are composed of cartilage, and not bone and they are covered by unique scales. Members of Class Osteichthyes posses jaws, but most have skeletons which consist entirely of bone.
3. What adaptations lead to the divergence of mammals? !
The extinction of the dinosaurs led to the rise of new species, such as mammals, who gradually distinguished themselves from other species by traits such as hair, and the nursing of live young.
4. Which two groups of vertebrates share the most recent common ancestor? !
Classes Reptilia and Aves share the most recent common ancestor.
Christopher Long
The Perch Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Osteichthyes Genus: Perca Species: Flavescens
I. Purpose: The purpose is to examine the Perch internally and externally by dissection. II. Materials: 1. 2. 3. 4. 5. 6. 7.
Dissection tray Perch Scalpel Scissors Forceps Dissecting Probe Dissecting Needle
III. Methods: A. External: The dissector began his analysis by measuring the length of the perch from anterior to posterior, and upon finding it to be 17 cm long, began a general examination of the perch's exterior. The dissector first noted that although the body of the perch subsisted of three subsections, including a pointy, short, head region, a long, thick trunk region, and a tubular tail section which branched into the caudal fin, certain characteristics were present throughout its exterior anatomy, including a surface composed of scales who's feel varied between scratchy and smooth depending on direction he approached them, a coloration that varied, at times ambiguously, between lightest pink and dark black, and a barely perceptible layer of slime, which coated the exterior. The dissector flipped his perch, so that the ventral side shew, and observed that the coloration on the underside of the perch to be white, tinted with orange, before he briefly probed the small anus with his dissection probe. The dissector then flipped the perch, so that it rested on its ventral surface, and began a detailed examination of the head section. The dissector noted that paired eyes of a dull blue color lay on either side of the perch's hard, tough skull, and that immediately between them, on the ventral–most surface of the perch lay two small, white openings known as sinouses, located inside of small pits. The dissector probed them with his dissecting probe, and deduced that they did not extend into the brain, as his probe reached the opening's end, before he found another set of sinus openings, created by a genetic irregularity, which astonished him. Next, the dissector located the anterior most point of his perch, the jaw, and identified it's two constituant parts; the black, hard maxilla, or upper jaw, and orange colored lower jaw, or mandible, that jointed to it from beneath. The dissector used his dissecting probe to pry apart the jaws, and then examined their interior. Extending upward from the lower jaw of the perch, the dissector found prickly, transparent teeth which curved slightly inward, and after examining the seemingly-toothless upper jaw, he located the smooth, pink tongue, slightly posterior to both structures, which filled most of the mouth cavity. The dissector then closed the jaws, and then examined a fleshy protrusion on the ventral side of the head, the white, smooth Isthmus, that divided the paired, hard, black gill coverings known as operculum, which extended downwards from the sides of the perch, and ran from the area behind the jaw, to the small, diamond–shaped pre operculum, that shared it's features. The dissector noted that the operculum extended over sections of both the head, and the trunk, before he lifted it, and saw a section of the soft, white, pink-tinted gill located underneath. Next, the dissector began a general analysis of the perch's trunk, beginning with the thin, black, lateral line, which extended from the head of the organism, and traveled through both the perch's trunk, and tail, extending dorsal to the gills along the side of the perch. The dissector then examined the non-paire dorsal fins of the animal, starting with the anterior dorsal fin, which he observed to be black in color, and composed of spines, and moving on to the posterior dorsal fin, which he observed to be of similar color, but smaller, and composed of soft rays. Posterior to these, at the end of the fishes tail, the dissector observed the singular black caudal fin, composed of soft rays, and underneath, a little to the anterior, he saw the lone anal fin, composed of rays and spines, while dorsal to this, on either side, he observed the paired, golden orange, pectoral fins, composed of two spines, and many soft rays. Lastly, the dissector observed the soft, clear, paired pectoral fins, located dorsal to the pelvic fins, just behind the operculum, and noted that between the rays or spines of each gill, there was a thin membrane of similar color, that held the fin together. The dissector the concluded his external observations, as there was nothing left to examine.
B. Internal: The dissector began his examination of the perch's exterior by locating the operculum, located toward the anterior of the perch, and by use of his scissors, making an incision from 1cm behind the fish's eye, and moving upward until the operculum's connection to the exterior was totally severed, revealing in its wake four pairs of soft, light-orange semicircular gills, attached to the perch's interior. Using his forceps, the dissector tugged out a single pair pair of gills, and carefully examined them, noting the thick, white cartilaginous gill arch that composed the core, the white, triangular, soft, tooth shaped gill rakers which projected from the gill arch toward the interior, and the soft, pinkish white gill filaments, which extended outward from the the gill arches in small folds. The dissector could not locate the capillaries, or observe any other feature of the gills, so he ceased examining them and placed the remaining gills in a pile on his dissecting tray. The dissector then inserted his scissors under the ventral integument through the perch's anus, and despite heavy resistance, cut along the length of the perch, halting about 1 cm from the eye, before cutting perpendicular to his previous cut, the dissector made an incision from the ventral side of the perch to immediately above the lateral line, and repeated the process, cutting through the integument which lay above the anus with his scissors. Using his scalpel, the dissector then made a horizontal cut through the tough muscle along the fish's side, and thus formed a window into the fish's body, which he carefully removed in order to see the fish's internal anatomy. The dissector began at the dorsal most point in his window, by examining the small, flexible, whitishclear ribs extending from the hard, segmented backbone, before he noted that layers of thick, tough orange muscle still covered half of the visible interior, and set out to remove the unwanted tissue with his scalpel, carefully peeling it from the fish's organs. Next, the dissector examined the elongated, soft black kidney, which ran along the dorsal most part of his window cut, slightly under the rib cage, and eventually tapered into the gray, slightly bulbous Bladder, which after a short run, dropped into the urogenital opening. The dissector then examined the area ventral to these, and observed the elongated, black membranes of the deflated swim bladder, before noting that the thin, tubular white esophagus ran ventral to it from the anterior of the perch, and into the stomach. The dissector ignored the stomach, but noted that the esophagus passed immediately over the fish's dark gray heart, located slightly beneath the space left by the gills, on its way to the fish's mouth, before he examined the heart in depth, noting that it was composed of both a large chamber known as the atrium, and a smaller, but more muscular chamber known as the ventricle, and was connected to the circular system by a large vein leading into the heart, and a large artery leading out. He could barely discern the sinus venosus, and conus arteriosus, located the anterior and posterior sections of the heart respectively, but could observe very little of either due the heart's small size, and could examine neither in depth. Following this, the dissector examined the area anterior to the stomach and ventral to the swim bladder, finding the bulbous, squishy, white stomach, which was largely overlapped by pairs of thin, white, tubular pyloric saecae held together by a central disk of tissue, and whose vental anterior side attached to both the small white gallbladder, and the larger, softer, white liver, both coattached to each other. The dissector than analyzed the long, tubular, double folded white intestine, which protruded from the posterior of the stomach, and eventually tapered off into the anus. From the exterior of one fold of the intestine, the dissector could partially discern the pancreas, however it was to indistinct for him to fully examine, and so he concluded analyzing the organs made visible through his window cut by noting the two pairs of gray, long, white tipped gonads, which extended behind the stomach, and marked his perch as a male. The dissector than moved to the perch's cerebrum, and using his scalpel, he made an incision into the fiercely resistant bone, traveling from 1 mm behind the middle of the eye, to a point approximately 1-cm away, and repeating this process on the other side, before he connected the two cuts, and removed the block of bone with little interference, revealing the perch's brain. At the brain's anterior most point, behind the sinuses, the dissector observed two pairs of small olfactory bulbs, connected by nerves to—
the thick cerebrum, which was anterior to the slightly smaller optic tectum, whose dorsal surface was attached to the equally sized cerebellum, and whose ventral surface attached to the long, large, medulla oblongata. Next, the dissector observed the thin, long, white spinal chord, which extended from the base of the medulla oblongata toward the posterior of the perch, and turned his attention back to the body. Using his forceps, the dissector removed a single scale from the perch's side, and carefully placed it on a slide, for examination under a dissecting microscope. The dissector found that under a microscope, the smooth scale appeared rough, extremely chunky, and thick, before he ended his dissection, as he could locate nothing else to examine
IV. Observations: A. External Anatomy of a Perch
IV. Observations: B. Internal Anatomy of a Perch
V. Conclusions: 1. Describe the teeth of fish and explain how their structure is adaptive to their diet. The translucent teeth of a perch lie on its jaw, and their primary use consists of capturing small organisms such as plankton. As an adaptation to their diet, the perch's teeth are small, and, and posses extremely extremely sharp points, as well as a closely knit distribution across the jaw, which aid in the ingestion of small organisms 2. Describe the location of the nostrils and explain where they lead The pitted nostrils of a Perch are used to locate prey via scent, and are located immediately anterior to the eyes, on the dorsal part of the perch's head. They lead a short way into the perch's cranium and halt, whereupon nerve chords transfer sensory information to the olfactory bulbs for processing. 3. Into what structure does the esophagus lead? The short tube known as the esophagus transports food from the mouth, behind which it begins, and the stomach, which it lead into. 4. Suggest a function of the spiny anterior dorsal fin. The Anterior dorsal fin of a perch is composed of many sharp spines, connected by a thin membrane, and aids the perch in remaining upright, and moving through the water in a straight line. 5. List all the fins and describe their location on the fish. Which are paired? Which fins contain spines? (answers in bold below) The non-paired anterior dorsal fin, composed of spines, and the non-paired posterior dorsal fin, composed of rays, lie on the dorsal surface of a perch. Behind both, at the total posterior of the fish rests the non-paired, ray-composed caudal fin, and anterior to it on the posterior ventral surface rests the non-paired anal fin, composed of both rays, and spines. Anterior to the anal fin, lie the paired pelvic fins, composed of rays, and a few spines, while finally, the paired pectoral fins project from either side of the fish, and are composed of soft rays. 6. Describe the scales on your fish. The scales on my fish had the appearance of small, smooth shiny shingles, all of which pointed away from the anterior of the fish, in order to facilitate swimming. Under a microscope, they were bumpy, and rough, and underneath them on the perch were located small glands to excrete slime. 7. What takes place in the gills? The gills are composed of four sets of gill arches with gill rakers branching to the interior. To the exterior, many smaller gill filaments connect, to form that body of the gill, which in turn contain small capillaries, through which blood travels during the process of gas exchange, that takes place in the gills. The gills also aid in ion transfer, ammonia filtration, and excretion. 8. What is the function of the gill filaments? The gill filaments are a double row of thin projections that extend from the gill arches, and serve to hold the capillaries. Inside them, most of the gill's primary functions occur. 9. Describe how circulation takes place in a fish.. Veins lead deoxygenated blood into a collecting chamber know as the sinus venosus, which in turn deposits the blood into a large chamber of the heart known as the atrium. Contractions of the atrium speeds up the blood, and drive it into the muscular ventricle, the heart's main pumping chamber. Here, contractions of the ventricle provide most of the force which drives blood throughout the entire circulatory system, and force blood into the elastic, valved, conus arteriosus, from which it travels along arteries into the gills, and undergoes—
gas exchange in small vessels called capillaries, before transporting oxygen and nutrients to other parts of the body, and traveling back to the heart. 10. Summarize your dissection experience. When I discovered that the class would carry out the dissection on separate days I became a bit worried, because we hadn't been issued dissection guides, however my doubts were soon assuaged, and I did fairly well, on the whole. At first I had a few problems identifying the heart, however after that, everything fell into place. I even discovered some structures (pyloric caeca), which were unlabeled in our book's original illustration, and found the experience interesting (my perch only had three). Another large surprise came when I noted that that that aside from the orange muscle, I could classify everything in almost “black and white� terms, regarding coloration. Unlike the previous dissection, I made my slide correctly, and I had no trouble locating my perch's brain in perfect condition. However the most enjoyable part came just as I thought it completed, and walked through the door. After being (voluntarily) press ganged by one of my instructor's delightful assosiates, I felt like something of a scientific missionary to the lower grades, displaying a fish heart for all to see. And though I still don't find dissection lovable in and of itself, I do know that I find many of the connected accidentals extremely enjoyable.
Christopher Long
The Frog Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Amphibia Order: Anura Genus: Rana Species: pipiens
I. Purpose: The purpose is to examine the Frog internally and externally by dissection. II. Materials: 1. 2. 3. 4. 5. 6. 7.
Dissection tray Frog Scalpel Scissors Forceps Dissecting Needle Dissecting Probe
III. Methods: A. External: The dissector began his dissection of the frog by observing the smooth, slimy skin, which hung loosely from the body, colored yellow on the ventral surface, and splotchy green on the dorsal surface, where the integument clung slightly tighter. He noted that the body of the frog consisted of a small head section connected to a larger trunk section by a short neck, and that from the trunk extended four pairs of legs, each of which held four fingers. The dissector then observed the two small, brown modified lateral lines, that protruded lateral to the frog's depressed backbone, and halted shortly beneath the frog's moderately sized black eyes, which were covered by three eyelids; the soft skinfold know as the upper eyelid, the flexible lower eyelid, and the hardy, transparent, nictitating membrane, which he probed using his dissection probe, and could not easily move. Lateral, and slightly ventral to the eyes, the dissector observed the flat, indented tympanums, while medial to the tympanums, and cranial to the eyes, he could see the small, white, pitted external nares, which he probed using his dissection probe, discovering that they ran a short while into the head, but did not reach the brain. The dissector next observed the frog's short, clawless forelimbs, located ventral and distal to the eyes, on the trunk of the frog, before he examined the dorsally located, muscular hind legs, which were slightly longer than the frogs body, and three times as long as the frogs forelimbs, possessing webbed feet, and unclawed toes, one extremely large in relation to the others. The dissector then flipped the frog to it's ventral side, and observed that he could see a portion of the large intestine through the skin, running medially from the limbs to the black opening known as the vent, which he then lightly probed using his dissection needle, and found to extend a moderate way into the frog. Next, the dissector then flipped his frog to the dorsal side, and probe the tight, closed jaws with his dissection probe, which could not go very far because of the jaws. Then the dissector held the frog, and using his gloved hand, broke the resistant jaws in half, and split portions of the frogs neck located proximal to it. Lining the dorsal interior of the frog's creamy mouth, the dissector saw many small, sharp, clear maxillary teeth, which were not present on the lower jaw. Proximal, and ventral these, on either side of the mouth's ventral portion, the dissector saw the small, impressed openings know as internal nares, which his probe could not go far into, while medial to the internal nares, the dissector saw grey, flat, twin vomerine teeth. Ventral to the vomerine teeth, between either side of the jaw, the dissector observed the shadowy esophagus, which he probed a brief way into using his dissection needle, finding it to be short and leading to the stomach, located medial to the larger openings of the Eustachian tubes, located on the dorsal surface of the jaw, which he did not prob into. Medial and ventral to the Esophagus, on the jaw's ventral surface, dissector observed a rounded structure he knew to be the glottis, which his dissection probe revealed to be the opening of the larynx, but lateral to it, could not observe any vocal sac openings, proving conclusively his frog was female. The dissector then observed that cranial to the glottis lay the frog's dark gray, bulbous, flat, cranially attached tongue, which at the uttermost caudal point, split into two small protrusions, and ended his external analysis. B. Internal: The dissector began his internal observations by flipping the frog to it's ventral side, removing most of the skin from the frogs body with his scalpel, incising first down the middle, and then making two lateral incisions proximal the legs on either side, to sever connection points, before pulling the rest of the skin of the frog's body with moderate ease, and observed the smooth, flexible, yellowish orange muscle beneath, which proved particularly numerous around the hind limbs. Next, the dissector—
—made an incision with his scalpel down the center of the stomach, and four smaller incisions lateral to this along the interior side of each limb. The dissector then tugged the two flaps created open, and observed the internal organs of the frog. Many tubular, rubbery, orange fat bodies obscured the dissectors view, so he removed them, and then proceeded. Toward the cranial end, the dissector observed a large, forest green, moderately soft, three lobed liver, which partially obscured and connected to the J-shaped, soft stomach, which was dirty orange in coloration, and ran laterally to it along the frog's left side. Tucked underneath the middle lobe of the liver, the dissector observed the green, soft gallbladder, which connected the middle lobe of the liver to caudal end of the stomach via a thin bile duct. The dissector removed the liver, and observed the gray, muscular, bulbous heart which rested cranial to it, consisting of the valentine-shaped ventricle, and the spherical left and right atriums, located cranial and lateral to it. Distal and lateral to these, tucked along either side of the frog's body cavity, the dissector observed two pairs of deflated, membraneous, purplish lungs, connected to the lobes of the heart via a network of veins and arteries, while cranial to them, he observed the small Esophagus, which connected to the stomach. The dissector removed both the lungs, and the heart, revealing the white backbone of the frog, and more of the orange internal muscle he had observed earlier. He followed the backbone caudally until he reach the thin, whitish yellow, dual-portioned, coiled small intestine; which he observed to consist of a cranial end know as the duodenum, which connected to the stomach, and a lower end known as the ileum, which ran caudally toward the small intestine; and was covered by a small the thin, clear membrane of mesentery. Located on the right side of the frog, and lateral to the lower portion of the small intestine; the dissector observed a small, yellow-white, slightly bulbous, tightly coiled tube, which he recognized as the frog's oviduct; and connected caudally to it, he saw the thick, straight, soft, white colored large intestine, that piped off into the short, thin tube of the cloaca, and eventually ran into the vent, located at the caudal end of the frog. Ventral to this, he saw the thin, deflated white membrane of the urinary bladder, which piped into the cloaca, and running laterally and proximal from the large intestine along the left side of the frog, the dissector saw the red, spherical, bulbous spleen; while located cranially, and slightly to the frog's right, the dissector observed the two reddish kidneys, ventral to the frog's small intestine; and dorsally cranial to this, the dissector saw small, white, brain-like pancreas, dorsal to the inestine. The dissector then flipped his flog to it's dorsal side, and searched for the brain. Using his scalpel, the dissector made an incision about 1 mm caudal from the right eye, and followed it over to the left, before he cut caudally about 5 mm, and then over again, creating a disk in the skull of the frog, which he then removed, revealing the brain. At the cranial end of the white, coiled brain, the dissector saw a pair of olfactory bulbs, which led caudally into the larger cerebrum, located cranial to the optic tectum. Caudal, and dorsal to the optic tectum, the dissector could observe the cerebellum, while caudal and ventral to it, the dissector saw the elongated medulla oblongata, which tapered into the spinal chord. The dissector noted a number of tiny nerves running out from the brain, and then ended his dissection, as there was nothing else to examine.
IV. Observations: A. External Anatomy of a Frog:
IV. Observations: B. Internal Anatomy of a Frog:
V. Conclusions: 1. Name two different functions of the skin The loose, thin skin of a Frog contains many capillaries, and serves a vital aid in gas exchange through the process of cutaneous respiration, due the small surface area of the lungs. Because of its permeability, the skin of a frog also allows for the absorption of water. 2. Name a function of the mucus glands. The mucus glands of a Frog excrete a lubricant that keeps the skin moist in air, and aids in gas exchange. In some species, they also excrete foul tasting, or poisonous substances 3. How many arteries does a frog have? The frog has three primary arteries, as well as many smaller arteries. The Carotid arches transport blood to the brain, the Aortic Arches transport blood the the body, and the Pulmocutaneous artery transports blood to the lungs. Other arteries include the renal artery, the gastric artery, the hepatic artery, the subclavian artery, and the iliac artery. 4. What is an adaptive value of the nictitating membrane? The transparent, movable nictitating membrane protects the eyes of a frog from chemical, bacteriological, and biological agents, without impeding vision. 5. Name four structures that empty their discharge into the cloaca. (answers in bold below) The large intestine, the gonads (ovaries and testes), the urinary bladder, and the kidneys all discharge into the frog's cloaca. 6. Name two ways that a frog's forelimbs differ from it's hind legs. The longer back legs of a frog posses a skeleton with several specializations for absorbing the forces created by jumping and landing, and webbed hind feet. 7. How is the tongue of a frog attached to its mouth? The muscular tongue of a frog is attached to the cranial end of the mouth so that the tongue can be flipped out and used to snare prey. 8. Where does the opening of the Glotis lead? The glotis is a small, rounded structure with a vertical slit, found just caudal to the tongue, which serves as the opening to the larynx and the lungs 9. How many chambers are there in a frogs heart. The tri-chambered heart of a frog consists of the left atrium, which contains only oxygenated blood, the right atrium, which contains only deoxygenated blood, and the muscular ventricle, which contains both oxygenated and deoxygenated blood, pumping them throughout the circulatory system. 10. Name the three arteries that branch from the Truncus Arteriosus The Carotid arches transport blood to the brain, the Aortic Arches transport blood the the body, and the Pulmocutaneous artery transports blood to the lungs. 11. How many lobes make up the liver of a frog? The large liver of a frog creates bile, and consists of three separate lobes; the right lobe, the left anterior lobe, and the left posterior lobe. 12. Why is the Gallbladder Green? The gallbladder serves as a storage area for bile, which tints it green. 13. What is the main function of mesentery? The mesentery is a small, thin membrane resembling a pastic wrap, which holds the small intestine in place. 14. What system does the kidney belong to? What is its main function? The kidneys of a frog serve as it's primary excretory organs, filtering the blood of harmful chemicals, and converting toxic ammonia into urea.
15. Summarize your dissection experience in two paragraphs: When I first walked into the dissection room, after three days of sickness with a virus, I didn't expect that my instructor would have me participate in the dissection, despite the rigorous study I'd been stocking up on. Needless to say, I was worried at first. Although I knew that my lab report would be graded fairly, I didn't want to seem like the proverbial dunce in the corner (though once the dissection began, this fear dissipated). With exception of a few structures inside the mouth I needed no help whatsoever for my external observations, and completed them with little hassle. Cracking open the frog's jaw was a little difficult— at first—however the jovial laughter of a female classmate, in equally difficult straights, deprived me of any shame. For some reason, even the preservatives smelt less cloyingly (though a little got on my face), and I went on to my internal observations with confidence and zing. The internal observations of my dissection were considerably more eventful, as I realized when I looked carefully at my tools. When the last class came through, someone dropped two forceps into my tray, rather than any scissors. To me, this came as a healthy surprise; from previous dissections, I'd come to prefer a scalpel. In any event, my dissection moved along at a rapid pace (to rapid I realized, when a frog leg flew into my lap). Most of the internal organs I found resembled those of a perch, and this familiarity, combined with a more familiar tool, allowed me to go ahead of the current instructions. The only organs I couldn't name at first sight were the kidneys and the pancreas, which my instructor determined for me, before I found my frog's (intact) brain. By this point, the stench had broken through my nostrils, so with some happiness, I cleaned out my tray, and found that missing pair of scissors, before tottering out of the classroom. Despite the pride of having completed a difficult dissection, my stomach rumbled. Sometimes, food is the last thing anyone has in mind‌
Christopher Long Science Mr. Snyder A.D. 2009
Heart Rate Lab: Purpose: In this lab I examine the affect of various actions on my heart rate: Heart Rate:
Walking
Jogging
Running
Beats per Fifteen Seconds
20
37
48
Beat per Minute
80
148
192
Beats per Fifteen Seconds After One Minute
16
23
30
Christopher Long Science Mr. Snyder A.D. 2009
Blood Type Lab: Background: Around 1900, Karl Landsteiner discovered that there are at least four different kinds of human blood, determined by the presence or absence of specific agglutinogens (antigens) on the surface of red blood cells (erythrocytes). these antigens have been designated as A and B. Antibodies against antigens A or B begin to build up in the blood plasma shortly after birth, the levels peak at about eight to ten years of age, and the antibodies remain, in declining amounts, throughout the rest of a person's life. The stimulus for antibody production is not clear; however, it has been proposed that antibody production is initiated by minute amounts of A and B antigens that may enter the body through food, bacteria, or other means. Humans normally produce antibodies against those antigens that are not on their erythrocytes: A person with A antigens has anti-B antibodies; a person with B antigens has anti-A antibodies; a person with neither A nor B antigens has both anti-A and anti-B antibodies; and a person with both A and B antigens has neither anti-A nor anti-B antibodies (Figure 1). Blood type is based on the antigens, not the antibodies, a person possesses. The four blood groups are types A, B, AB, and O. Blood type O, characterized by the absence of A and B agglutinogens, is the most common in the United States and is found in 45% of the population. Type A is next in frequency, and is found in 39% of the population. The frequencies at which types B and AB occur are 12% and 4% respectively.
Blood Type:
Agglutinogens:
Figure I: Antibodies in plasma
A:
A
Anti-B
A, AB
O, A
B:
B
Anti-A
B, AB
O, B
AB:
A and B
Neither
AB
O, A, B, AB
O:
Neither A nor B
Both
O, A, B, AB
O
Can Give Blood To:
Can Receive Blood From:
The ABO System and Process of Agglutination: There is a simple test performed with antisera containing high levels of anti-A and anti-B agglutinins to determine blood type. Several drops of each kind of antiserum are added to separate samples of blood. If agglutination (clumping) occurs only in the suspension to which the anti-A serum was added, the blood type is A. If agglutination occurs only in the anti-B mixture, the blood type is B. Agglutination in both samples indicates that the blood type is AB. The absence of agglutination in any sample indicates that the blood type is O (Figure 2)
Figure II: Reaction: Blood Type:
Anti-A Serum:
Anti-B Serum:
Agglutination
No Agglutination
A
No Agglutination
Agglutination
B
Agglutination
Agglutination
AB
No Agglutination
No Agglutination
O
The Importance of Blood Typing: As noted in the table above, people can receive transfusions of only certain blood types, depending on the type of blood they have. If incompatible blood types are mixed, erythrocyte destruction, agglutination and other problems can occur. For instance, if a person with type B blood is transfused with blood type A, the recipient’s anti-A antibodies will attack the incoming type A erythrocytes. The type A erythrocytes will be agglutinated, and hemoglobin will be released into the plasma. In addition, incoming anti-B antibodies of the type A blood may also attack the type B erythrocytes of the recipient, with similar results. This problem may not be serious, unless a large amount of blood is transfused. The ABO blood groups and other inherited antigen characteristics of red blood cells are often used in medico-legal situations involving identification of disputed paternity. A comparison of the blood groups of mother, child, and alleged father may exclude the man as a possible parent. Blood typing cannot prove that an individual is the father of a child; it merely indicates whether or not he possibly could be. For example, a child with a blood type of AB, whose mother is type A, could not have a man whose blood type is O as a father. The Genetics of Blood Types: The human blood types (A, B, AB, and O) are inherited by multiple alleles, which occurs when three or more genes occupy a single locus on a chromosome. Gene IA codes for the synthesis of antigen (agglutinogen) A, gene IB codes for the production of antigen B on the red blood cells, and gene i does not produce any antigens. The phenotypes listed in the table below are produced by the combinations of the three different alleles: IA, IB, and i. When genes IB and IA are present in an individual, both are fully expressed. Both IA and IB are dominant over i so the genotype of an individual with blood type O must be ii (Figure 3).
Figure III: Phenotype
Possible Genotypes
A
IA IA
B
IB I B , I B i
AB
IAIB
O
ii
Use IA for antigen A, IB for antigen B, and i for no antigens present. Genes I A and IA are dominant over i. AB blood type results when both genes IA and IB are present.
The RH System: In the period between 1900 and 1940, a great deal of research was done to discover the presence of other antigens in human red blood cells. In 1940, Landsteiner and Wiener reported that rabbit sera containing antibodies for the red blood cells of the Rhesus monkey would agglutinate the red blood cells of 5% of Caucasians. These antigens, six in all, were designated as the Rh (Rhesus) factor, and they were given the letters C, c, D, d, E, and e by Fischer and Race. Of these six antigens, the D factor is found in 85% of Caucasians, 94% of African Americans, and 99% of Asians. An individual who possesses these antigens is designated Rh+; an individual who lacks them is designated Rh-. The genetics of the Rh blood group system is complicated by the fact that more than one antigen can be identified by the presence of a given Rh gene. Initially, the Rh phenotype was thought to be determined by a single pair of alleles. However, there are at least eight alleles for the Rh factor. To simplify matters, consider one allele: Rh+ is dominant over Rh-; therefore, a person with an Rh+/Rh- or Rh+/Rh+ genotype has Rh+ blood. The anti-Rh antibodies of the system are not normally present in the plasma, but anti-Rh antibodies can be produced upon exposure and sensitization to Rh antigens. Sensitization can occur when Rh+ blood is transfused into an Rh- recipient, or when an Rh- mother carries a fetus who is Rh+. In the latter case, some of the fetal Rh antigens may enter the mother’s circulation and sensitize her so that she begins to produce anti-Rh antibodies against the fetal antigens. In most cases, sensitization to the Rh antigens takes place toward the end of pregnancy, but because it takes some time to build up the anti-Rh antibodies, the first Rh+ child carried by a previously unsensitized mother is usually unaffected. However, if an Rh- mother, or a mother previously sensitized by a blood transfusion or a previous Rh+ pregnancy, carries an Rh+ fetus, maternal anti-Rh antibodies may enter the fetus’ circulation, causing the agglutination and hemolysis of fetal erythrocytes and resulting in a condition known as erythroblastosis fetalis (hemolytic disease of the newborn). To treat an infant in a severe case, the infant’s Rh+ blood is removed and replaced with Rh- blood from an unsensitized donor to reduce the level of anti-Rh antibodies.
Objectives: ! ! ! ! !
Define Agglutination and agglutinin Perform an actual blood typing procedure Observe the antigen/antibody reaction in blood Determine the ABO and Rh blood type of your own blood analyze class data to determine if it is representative of the human population
Materials: Material Needed per Group: ! ! ! ! ! ! !
Two sterile alcohol pads One sterile lancet One Blood typing tray Three toothpicks Gloves Goggles Apron
Shared Materials: ! ! ! !
Anti-A typing serum Anti-B typing serum Anti-Rh typing serum Biohazard bag
Procedure: Safety: ! !
Protective gloves, goggles, and face shield should be worn when handling blood samples or when in contact wit contaminated materials. Dispose of all contaminated items in the included biohazard bag and placed in a properly labeled biomedical waste container.
ABO and Rh Blood Typing: 1. Thoroughly clean the tip of one finger on your non-writing hand with a sterile alcohol pad. 2. Carefully open a sterile lancet package from the end that is closest to the blunt end of the lancet and remove it. 3. Prick the sterile area on your finger with the lancet. 4. Carefully place the lancet back in its package and dispose of it in the biohazard bag. !
If you cannot perform this step, as your teacher for assistance
5. Add one drop of blood to each well of the blood typing tray
6. Clean the tip of your finger with another sterile alcohol pad and dispose of it in the biohazard bag. 7. Add one drop of anti-A serum to the A well of your blood typing tray, one drop of anti-B serum to the B well, and one drop of anti-Rh serum to the Rh well. 8. Using a clean toothpick, stir the A well thoroughly. Dispose of the toothpick in the biohazard bag. 9. Repeat the above step for each of the B and Rh wells. Be sure to use a new toothpick for each well to avoid cross-contamination. Dispose of each toothpick in the biohazard bag when you are done stirring each well. 10. Examine each well for agglutination. Agglutination indicates a positive text result. !
Clumping in a tray may indicate agglutination
11. Record your results in Table One in the Analysis section and determine your blood type. 12. Pool the class data and calculate the percentage of students with each blood type using the following formula: !
(Total number of students with type X blood/Total number of students in the class)*100
13. Record your results in Table Two
Analysis:
Blood Sample
Blood Type
Anti-A Serum
Table I: Anti-B Serum
Anti-Rh Serum
Blood Type
A
Anti-B
A, AB
O, A
Table II: # of Students With Total # of Students in Blood Type Class
A
3
B
0
AB
1
O
6
% of Students with Blood Type 30%
10
0% 10% 60%
Assessment: 1. Answer the following questions based on your ABO blood type. Ignore the Rh factor for this question. a) What agglutinins are found in your plasma? !
Anti-A and Anti-B antibodies
b) What agglutinins are found in your plasma? !
None whatsoever
c) If you needed a blood transfusion, what blood types could you safely receive? !
O
d) If you donated blood, what blood type(s) could safely be transfused with your blood? !
AB, B, A, O
2. Below is a description representing the blood type analysis of a new patient (Patient X). From the information obtained from the “slide�, fill out the medical technologist's report. a) Blood Typing Tray !
A Well: Agglutination
!
B Well: No Agglutination
!
RH Well: Agglutination
b) Medical Technologist's Report !
Patient Name: Christoph Lang
!
ABO Type: A
!
Rh type: +
!
Med Tech Name: Herr Snyder's Klasse
Christopher Long Science Mr. Snyder A.D. 2009
Nutrients Lab: Purpose: This lab depicts a diet containing all essential nutrients for human life: Meal:
Contents of Meal:
Nutrients:
Breakfast
Peaches soaked in Cream
Carbohydrates, Water
Lunch
Potato Soup and Red Wine
Proteins, Lipids, Water
Dinner
Shrimp, Scallop, Lobster, Crab, Clam, Caesar Salad, and German Beer
Minerals, Vitamins, Water
Dessert
Scones with Tea
Vitamins, Water
Christopher Long Biology I Mr. Snyder A.D. 2009
Fir! Year Biology: Many different approaches cover the difficult subject of first year biology, and none perhaps grants the student a complete understanding of either biology, or the scientific methods employed in this field. Yet despite the disparity of methods, and necessary lack of complete understanding, any genuine course of biology must confront several of the notions most fundamental to the human understanding of life. Firstly, the aspiring biologist must confront the building blocks of life, and understand them to a degree sufficient for an understanding of more complex organisms. Second, he must develop an understanding of life's immense range, and diversity. Finally, he must examine the pinnacle of life, and explore the human body, created in millennia of evolution's blast furnace. In this essay, I will explore how the development of my first first year biology course traced these steps.
Nothing holds a more perennial glee for young children then asking “Why ?”, and a whole field of biology serves to answer the age old question of both why, and how, life functions. Because at it's most fundamental level, life is composed of cells, my class gained a good initial understanding of concepts relating to cellular biology. We learnt the the mechanics which underly life's transmission, — The genetic code— and also explored the various chemical processes which allow cells to function, and the organelles behind them; we learned of transcription and translation, ribosomes and nuclei. It was this analysis of life's most basic structure and function which permitted the class to flourish later in the course. When we learnt of cellular components such as DNA, it provided us a vital insight into concepts we had not yet learned, such as the evolutionary diversity of life. Similarly, experiments
performed to increase our knowledge of biology's most basic elements proved useful in the future, providing us with firm examples of the scientific method. Thus, the work we did relating to cellular biology and genetics put us in an excellent position to deal with more complex organisms, and natural processes. It formed a sturdy backbone for the course.
When most people imagine life , they imagine the mammals— and entirely dismiss almost every organism on the planet. In reality, the diversity of life on earth is so great that one critical element of biology is simply to recognize it's depth. The processes which enable this vast diversity of life; the methods of cellular formation, reproduction, organ growth to name a few, comprise the functional core of biological understanding. For our class, confronting this broad concept engendered the most intensive part of the year. We learnt the basic system of biological nomenclature, from kingdom to species, studied the way in which individual animals adapt to their environment , and examined the mammals, earth's most complex organism's. Moreover, we learned what had created the diversity we saw, becoming familiar with the concept of Darwinian Evolution and many of it's corollaries, such as natural selection. Nor did study alone did not constitute our duty: the class completed myriad dissections, upon animals of ever increasing complexity, noting the simple intricacy of nature, and the many intriguing similarities every specimen held in common. The more we studied, the more complete our picture of the natural world became, and the closer we came to the level of excellence where we could examine man, as the culmination of our biological studies. Understanding the vastness of life enabled us to better understand our own uniqueness both as organism's formed through years of development, and as human beings.
On earth, a single predator stands at the pinnacle; Man. No other organism has the capacity not only to hunt any species at will, but also to surpass the very principles of nature herself, and moreover, the human body provides biologists with the most extraordinary example of complexity in their grasp.
With this spirit, my class dove into our exploration of the human person. We examined the basic composition of the human body, and carefully studied each system. We learnt about the tissues which composed the systems. We learnt about the nutrients which sustained the tissues: we used all the knowledge we gained from previous exercises, and at last, we saw how everything we'd learned up till now worked in concert, and marveled at the symphony. Concepts before purely hypothetical, such as genetics, and lab experiments of only technical note began to actually influence our lives, just as modern biology has influenced life behind the scenes. Once, we first discovered the genes which affected human blood type, and then married genes with practical science in an experiment which let us find our blood type; information essential for transfusions. In the unlikely case that a friend is seriously injured, knowing the primary veins and arteries could help save a life. Because the class learnt how bones grow, we have a better idea of how to let them heal. And on a human level, knowing more about ourselves, and our place in a hierarchy much wider than even our entire species led to a greater understanding of the individual's place in human society. Studying Man was a perfect end for the course, and it allowed for both an overview, and a learning experience.
In my first year Biology course, I learnt many things. I learnt about the human body, about tissues and ligaments; about the immensity of life, how evolution helped create it; and about life's basic unit of structure and function, the cell. Along the way, sometimes the class laughed, and other times we suffered, (The blood type lab was painful) however the course fully met our expectations. Not only did it give us a firm biological foundation; it also helped us to understand our place in the cosmos.