Chapter 13

In humans, red-green color blindness is an X-linked recessive trait. If a man with normal vision and a color-blind woman have a son, what is the chance that the son will be color-blind? What is the chance that a daughter will be color- blind?

In Drosophila, white eyes is an X-linked recessive trait. A whiteeyed female is crossed with a male with normal red eyes. An \(\mathrm{F}_{1}\) female from this cross is mated with her father, and an \(\mathrm{F}_{1}\) male is mated with his mother. What will be the phenotypic ratios for eye color in the two sexes of the offspring of the last two crosses?

Can a linkage map be made for a haploid organism that reproduces sexually?

All mammals have evolved from a common ancestor. However, the chromosome number varies among mammals. By what mechanism might this have occurred?

How would the effects of natural selection differ on alleles that cause diseases fatal in childhood (such as progeria) and those that cause diseases that shorten life expectancy to 40 or 50 years (such as cystic fibrosis)?