[Campbell Biology P.1093] Which of the following statements accurately distinguishes the fast... | Practice Question
Which of the following statements accurately distinguishes the fast block from the slow block to polyspermy in sea urchin fertilization?
A: The fast block is achieved by the formation of the fertilization envelope, while the slow block involves membrane depolarization.
B: The fast block is permanent and irreversible, whereas the slow block is temporary.
C: The fast block is due to membrane depolarization, while the slow block involves the release of cortical granule contents and the formation of the fertilization envelope.
D: Both the fast and slow blocks are initiated by the acrosomal reaction.
Explanation
The text states that fusion triggers depolarization, which acts as a fast block to polyspermy Figure 47.2, point 3 . It also states that cortical granules fuse, and their contents cause the fertilization envelope to form, acting as a slow block to polyspermy Figure 47.2, point 4 .