Question

Father has red/green color blindness and is a hemophiliac. Mother is normal. Have two female children (Both are probably carriers). One female offspring marries a normal male. The question is what is the probability that their son is both color blind and hemophiliac? Originally I thought the chance is 25%. I am pretty sure that is incorrect or q^2 = 0.25 or 0.5. I have had difficulty with the assignment. Some advice would be helpful or a solution.

Answer 1

Even if the daughters are carriers, the dominant genes from the father will keep the characteristics from being expressed in the phenotype.