Sex-Linked traits: In man, normal vision is a sex-linked trait and its gene is dominant to the allele for red.

Sex-Linked traits: In man, normal vision is a sex-linked trait and its gene is dominant to the allele for red-green colour blindness. When a colour blind woman marries a man with normal vision, what would be the expected distribution of color vision among (a) their sons, and (b) their daughters?

Sex-Linked traits: In man, normal vision is a sex-linked trait and its gene is dominant to the allele for red.
Sons=100% color blind


daughters=100% carriers





Since color blindness is a sex linked recessive trait, a woman has to have the mutated gene on both her X chromosomes. And since the sons X chromosome always will come from the mother, her sons will always be color blind. The daughters will get one X from their mother, and the other form their father, and since he is not color blind they will only be carriers.