Fertilization is characterized by
A) a sperm's fertilin proteins binding to the follicle's integrin molecules
B) a block to polyspermy
C) multiple sperms penetrating the ovum
D) blastocyst formation
E) a block to polyspermy and blastocyst formation

Question

Quizplus · Accepted Answer

Fertilization is characterized by a block to polyspermy, which prevents multiple sperms from penetrating the ovum. Option A is partially correct, as fertilin proteins on the sperm's outer membrane do bind to molecules on the follicle cells surrounding the ovum, but this is not the defining characteristic of fertilization. Option D is incorrect, as blastocyst formation occurs after fertilization and is not a defining characteristic of fertilization itself. Option E is also incorrect, as the block to polyspermy is already included in option B, and blastocyst formation is not a defining characteristic of fertilization.

Fertilization Is Characterized by