Chapter 33
Biology: A Guide to the Natural World · 3 exercises
Problem 1
When a couple is having trouble conceiving a child, the first thing fertility specialists generally will look at is the fertility of the prospective father. What do you think a specialist would be looking for?
5 step solution
Problem 2
Most mammals are "placental," which is to say their embryos get nourishment within the mother through the placental system of blood vessels reviewed in the text. By contrast, amphibian and reptilian embryos are nourished by substances contained in eggs the mother lays. Can you think of any advantages mammals derive from the placental means of development? Can you think of any disadvantages?
3 step solution
Problem 3
Forty years after birth control pills for women came into widespread use, there is still no birth control pill for men. One reason for this is the basic difference between female production of an oocyte each month and the male production of sperm. Why should it be easier to suppress fertility in women than in men?
3 step solution