1. A dog has 39 pairs of chromosomes. Considering only independent assortment (the random lining up of maternally and paternally derived chromosomes), how many genetically different puppies are possible from the mating of two dogs? Is this number an underestimate or an overestimate? Why

2. Why is it extremely unlikely that a human child will be genetically identical to a parent?

3. Many male veterans of the Vietnam War claim that their children born years later have birth defects caused by a contaminant in the herbicide Agent Orange used as a defoliant in the conflict. What types of cells would the chemical have to affect in these men to cause birth defects years later? Explain your answer.

4. Why is a fertilized polar body unable to support the development of an embryo, while an oocyte, which is genetically identical to it, can?

5. How do the structures of the male and female human gametes aid them in performing their functions?