Hemophilia is an X-linked recessive allele causing a blood disorder. What are the chances that a daughter of a normal man and a woman, who is heterozygous for the disease, will have hemophilia?
A) 0%
B) 25%
C) 75%
D) 100%

Question

Quizplus · Accepted Answer

Since hemophilia is an X-linked recessive disorder, a daughter would need to inherit two copies of the recessive allele to express the disease. A normal man (XY) cannot pass the hemophilia allele to his daughters, and a heterozygous woman (XHXh) can only pass one affected X chromosome. Therefore, the daughter will be a carrier (XHXh) but will not have hemophilia.

Hemophilia Is an X-Linked Recessive Allele Causing a Blood Disorder