Answer:
D) She should look at her notes to find an example that shows exactly why she disagrees.
Explanation:
Answer:
1/4 suffer from hemophilia
1/4 are heterozygous
Explanation:
So since they are normal but their son isn't it is assumed that the mom is the carrier since the dad has to be X^HY
X^HY x X^HX^h
Set up a pedigree
X^HX^H X^HX^h
X^HY X^hY
1/4 suffer from hemophilia (X^h)
1/4 are heterozygous (X^HX^h)
A person can only show a recessive trait if both of their parents carried at least one copy of each of the recessive allele. The parents do not need to show the trait, as one copy is not enough to reveal it, but they must both carry it.
Hope this helped!