Hemophilia A is an X-linked recessive disorder.If a normal man marries a woman who is a carrier,what fraction of their daughters will have hemophilia?

Question

Quizplus · Accepted Answer

Since the man is normal, he must have two normal X chromosomes (XY) and the carrier woman has one normal X chromosome and one X chromosome with the gene for hemophilia (XhX). Therefore, their daughters will have a 50% chance of inheriting the hemophilia gene from their mother but they will always receive a normal X chromosome from their father. This means they will be carriers but will not express the disease. None of their daughters will have hemophilia itself.

Hemophilia a Is an X-Linked Recessive Disorder