Question

Color blindness is a common, recessive X-linked disorder. Normal vision (XN) is dominant to color blindness (XC). If a color blind man has a child with a woman who is a carrier for the disorder, what is the probability that the child would be color blind?

Answer 1

Explanation:

Let N be normal

Let n be for color blindness

A carrier gene would be Nn and the colour blind guy would be nn

Parental Phenotype: Carrier × Colour Blind

Parental Genotype: Nn × nn

Random Fertilization: *show box diagram*

Offspring Genotype : Nn, Nn, nn, nn.

Offspring Phenotype: Carrier, Carrier, CB, CB.

Probability that the child would be colour blind is 2:4 which is 1/2 or 50% or 0.5 chance.