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University of Calgary

Faculty of Science


Midterm examination II

CMMB 403 Developmental biology


November 17, 1999 Time: 50 minutes


Write your name on the first page, and your Student ID number on the following pages.

Use pen, not pencil.

If you do not understand a question, ask the instructor.

The number of marks allotted for each question is shown in brackets after the question.

The total number of marks is 43.


1. Postulate how cellular adhesion molecules might fit into the theories of specific and selective cell adhesion. (5)

2. From our discussions regarding cloning of nuclei from differentiated mammalian cells, what are the 3 most important steps required to favour success, and why? (6)

3. Suppose you are working in the lab of Dr. Frank. N. Stein, who desperately wants to create a two-headed tadpole. Knowing the unpredictable temperament of your boss, you decide to maximize your chances of success by using several fairly different approaches. Briefly explain 3 of the approaches you might use. (6)


4. Suppose you are studying the genetics of coat color in mice. You’ve discovered an unusual mutant phenotype: a mouse with a bright purple mohawk. You mate your only mohawk mouse, a male, with a normal female mouse, and observe that all the progeny have purple mohawks. You take one of these females and mate it with a normal male; all of their progeny look normal. Propose a model to explain these results. (4)


 5. Discussion the distinction between mosaic development and regulative development. (8)

Give an example of each. (2)



6. Considering the model we discussed in class for mesoderm and neural induction in Xenopus, what might be the effect of a mutation in the Vg-1 gene such that only a relatively low concentration of Vg-1 protein was expressed? Explain in detail. (12)


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