Color Blindness Problem Set

Problem 4: Genotype of Audrei's sister Caroline

What is the genotype of Audrei's sister Caroline, who has normal vision?

A.	homozygous for the dominant, normal vision allele
B.	heterozygous carrier of the red-green color blind allele
C.	homozygous recessive for the red-green color blind allele
D.	cannot be determined from the information given

Caroline, Audrei, and Liz, the three daughters, have inherited one X-chromosome from each parent. They each received the X-chromosome with the red-green color blind allele from the father. Caroline received the normal allele on the X-chromosome from the mother, while Audrei and Liz got the X-chromosome with the red-green color blind allele from the mother.