BIO - Pre-Lab Questions (Lab 3)

In an evolutionary tree, what does the trunk represent?

What two types of molecules would a molecular biologist study to determine evolutionary relationships

Why is it more useful to do a comparison of 3 or more organisms than just two?

What will our control organism be in the experiment today?

Using Indirect Measurements

Evolutionary Relationships between Domesticated Animals

Procedure
1. There is a culture dish filled with an agar gel. In this gel you will poke seven holes in a circular pattern with one hole in the middle of the circle. As seen in figure 1 and figure 2.
Figure 1.

2. After poking the holes, on the bottom of the dish write next to each hole the following.
1) Anti for Cow serum antibodies
2) D for donkey serum
3) G for goat serum
4) C for cow serum
5) H for horse serum
6) S for sheep serum
7) C for chicken serum
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3. Once you’ve completed labeling, pipet 15 uL of the appropriate substance into the proper well.
4. Next week we will exam the gels and come up with conclusions. The plates will resemble figure 2.
Figure 2.

Questions
1. Compare the serum proteins from the various mammals in terms of immunological properties. Do you think these properties are a reliable index for studying evolutionary relationships? Explain your answer.
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2. Describe how your results would have been affected if the antiserum was made in rabbits against duck serum proteins.
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3. Why is it important to include a cow serum sample along with the other species?
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