Hemophilia is a genetic disorder that causes a protein required for normal blood clotting to be missing. In a cross with a mother who carries the allele for hemophilia and a father who has normal blood clotting what would be the phenotypes of the offspring?

Aone female normal, one male normal, one female carrier, one male with hemophilia
Ball females carriers of hemophilia, all males normal
Call females normal, all males with hemophilia
Dall females normal, all males normal

Verified Answer :

Because the father is not a carrier, we know that his X and Y are both dominant non-carriers.  The mother is a carrier, but does not show symptoms, therefore she is mixed Xx with the lowercase x being the recessive hemophilia trait.  Their children would be XX, XY, Xx, and xY.  If Hemophilia is only passed on through the X chromosome, the correct answer would be A.

A is the correct answer!