Question

In humans, red-green color blindness is inherited as an X-linked recessive. If a color-blind woman marries a man with a normal vision what will be the expected phenotypes of their children with respect to this trait?

Answer 1

The expected phenotypes are that the males would be colour blind while the females still possess normal vision in their phenotypes (heterozygous in genotype).

Step-by-step explanation:

Since this trait is inherited as an X linked recessive trait, for a female to be affected she has to carry the recessive trait on both X chromosomes. but a male only need to carry the one recessive copy on his one X chromosome. let c rep the recessive trait. Thus, we have:

color-blind female x normal vision male

Xc Xc

XC XCXc XCXc

Y XcY XcY

The expected phenotypes are that the males would be colour blind while the females still possess normal vision in their phenotypes (heterozygous in genotype).