A couple has a daughter who is color-blind. The mother is not color-blind, but the father is. What is the genotype of the mother for this trait?
A) two dominant alleles
B) one dominant allele, one recessive allele
C) three dominant alleles
D) one abnormal Y chromosome, one normal X chromosome
E) two recessive alleles

Question

Quizplus · Accepted Answer

The mother must be a carrier of the color-blindness allele, meaning she has one normal vision allele (dominant) and one color-blind allele (recessive). Since the daughter is color-blind, she must have inherited the recessive allele from both parents.

A Couple Has a Daughter Who Is Color-Blind