What is happening in this picture?
Male ejaculate contains millions of sperm; the ovary re-
leases a single secondary oocyte. For fertilization to occur,
one sperm must penetrate the oocyte plasma membrane
and fuse with its nucleus.
stop fertilization by multiple sperm?
2. What role does the sperm play in oocyte
(Check your answers in Appendix C.)
Which cell nurtures and protects the developing sperm?
b. Sertoli cell
c. Leydig cell
d. epididymal cell
Use this figure to answer questions 2-4.
Which of the labeled structures secretes progesterone?
3. Which of the labeled structures can be fertilized by a sperm?
4. The process shown in D is triggered by______.
a. continuous periodic secretion of FSH
b. continuous secretion of estrogen
c. a surge of LH
d. continued secretion of progesterone
508 CHAPTER 16
The Reproductive Systems