Question: A human female "carrier" who is heterozygous for the recessive, sex-linked trait red color blindness, marries a normal male.
a. What proportion of their female progeny will show the trait?
b. What proportion of their male progeny will show the trait?
c. If one of their daughters marries a normal male, what is the probability that the first son of this marriage will show the trait?
d. If one of their daughters marries a normal male, what is the probability that the first child of this marriage will show the trait?