Question

A type of red-green color blindness is caused by an Xlinked recessive allele. A color-blind man and a woman with normal vision, whose father was color blind, plan to start a family. What is the probability that they will have a color-blind child?

Answer 1

Hello

Color blinness is X- linked recessive disease

Genotype of Man = XcY ( Xc is  allele of color blindness)

Genotype of Woman = XcX

(As her father is color blind therefore she has one allele Xc and one normal allele X and she is carrier of the disease)

Probabilty of their child being a color blind is 1/2 or 50% for both boy child and girl child.