Hemophilia is a sex-linked recessive trait in humans. If a father and a son are both hemophiliacs, but the mother is normal, her genotype must be. (Note: the H's are superscripts.) * XhXh XHXh XHXH XhY

XHXh (Note: the H's are superscripts.)

Explanation:

Hemophilia is a sex-linked recessive trait which means that the males having one altered copy of the gene is enough to cause the medical condition( as they have only one X chromosomes and females have two)

In this case the genotype of father and son is such that they are affected by hemophilia.The son has mother's X chromosome and father's Y chromosome.

XhY is the genotype of father and son. As mother would be heterozygous because she is not affected, her genotype will be XHXh.

what's the rest of the question

it marks things for degradation via the proteasome. it alters there celluar location.