Chapter 27

Match each function with the correct structure a. vas deferens b. prostate gland c. endometrium d. testis e. follicle f. uterus g. OVary h. oviduct Site of spermatogenesis

After a sperm penetrates an egg, it is important that the vitelline layer separate from the egg so that it can a. secrete important hormones. b. enable the fertilized egg to implant in the uterus. c. prevent more than one sperm from entering the egg. d. attract additional sperm to the egg.

12\. How does a zygote differ from a mature egg? a. A zygote has more chromosomes. b. A zygote is smaller. c. A zygote consists of more than one cell. d. A zygote divides by meiosis.

A woman had several miscarriages. Her doctor suspected that a hormonal insufficiency was causing the lining of the uterus to break down, as it does during menstruation, terminating her pregnancies. Treatment with which of the following might help her remain pregnant? a. oxytocin b. follicle-stimulating hormone c. luteinizing hormone d. prolactin

The embryos of reptiles (including birds) and mammals have systems of extraembryonic membranes. What are the functions of these membranes, and how do fish and frog embryos survive without them?

Should parents undergoing in vitro fertilization have the right to choose which embryos to implant based on genetic criteria, such as the presence or absence of disease-causing genes? Should they be able to choose based on the sex of the embryo? How could you distinguish acceptable from unacceptable criteria? Do you think such options should be legislated?