February 8, 1994 TIME: 50 minutes

TOTAL POINTS: 60

(VALUE) QUESTION

(20) 1. What is the function of ZP-3? Cite experimental evidence to support your statements.

(20) 2. Describe the molecular events that are responsible for the production of ribosomes during oogenesis in Xenopus.

3. Define or describe

(5) a. fast block to polyspermy in sea urchins.

(10) b. cyclin

(5) c. Sertoli cells.