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University of Calgary

Faculty of Science


Midterm examination I

CMMB 403 Developmental biology


October 18, 1999 Time: 50 minutes


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

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

The number of marks allotted for each question is shown to the left of that question.

The total number of marks is 50.


1. As we discussed in class, mouse sperm contain a plasma membrane protein called fertilin, which binds to an egg plasma membrane receptor to initiate membrane fusion. Suppose you are studying gamete membrane fusion in chimpanzees, and have identified a protein in the sperm membrane which binds to the egg membrane, and which is homologous to fertilin. In general terms, how might you go about identifying the receptor for chimp fertilin in the chimp egg plasma membrane?


2. It has been suggested that the use of androgens to build muscle mass may result in male sterility. Considering what you know about the hormonal control of spermiogenesis, explain why this might be the case.


3. Describe a mechanism of cleavage in which karyokinesis and cytokinesis are not linked. What kind of organism displays this cleavage pattern?

(I'm not looking for cleavage pattern terminology, but a description of what happens)


4. Suppose you have isolated a strain of mutant Drosophila females, who are able to produce offspring; however, their offspring are sterile. What kinds of questions might you pose to further investigate the nature of this mutant?


8 5. Gurken controls the anterior/posterior and dorsal/ventral polarity of the Drosophila egg. Briefly describe the roles of the following structures in the establishment of anterior/posterior oocyte polarity by Grk. In each case, briefly describe (in a sentence) the evidence that suggests the role for a given structure.



Posterior follicle cells:


6. Describe the regulation of cell cycle events in the Xenopus oocyte, fertilized egg, and cleavage stage embryo. (Depth should be the same as covered in class)

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