Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents? A) X^cXc and X^cY B) X^cXc and X^CY C) X^CXC and X^cY D) X^CXC and X^CY E) X^CXc and X^CY

Question

Quizplus · Accepted Answer

Red-green color blindness is a sex-linked recessive trait, and the son is color-blind, which means he inherited an X chromosome with the color blindness allele from his mother. Therefore, the mother is a carrier of the color blindness allele and her genotype must be XCXc. The father must be XCY because he has normal color vision. Therefore, the genotypes of the parents are X^CXc for the mother and X^CY for the father. Choice E is the only option that matches these genotypes.

Red-Green Color Blindness Is a Sex-Linked Recessive Trait in Humans