A human female is heterozygous for a recessive X-linked trait.She has children with a male who does not have the trait.Their sons have a _______ probability of expressing the trait, whereas their daughters have a _______ probability of expressing the trait.
A) 0; 0
B) 0.25; 0.25
C) 0.5; 0
D) 0.5; 0.5
E) 1; 0.5

Question

Quizplus · Accepted Answer

Sons have a 0.5 probability of expressing the trait because they receive their X chromosome from their mother, who is a carrier. Daughters have a 0 probability of expressing the trait because they must inherit two copies of the recessive allele to express the trait, but their father does not carry the allele.

A Human Female Is Heterozygous for a Recessive X-Linked Trait