A couple is planning to have a child. The female is a carrier for hemophilia; the male does not have hemophilia. What is the chance that a female child will never develop hemophilia?
A) 0%
B) 25%
C) 33%
D) 50%
E) 100%

Question

Quizplus · Accepted Answer

A female child will inherit one X chromosome from each parent. Since the father does not have hemophilia, he will pass on a normal X chromosome. The mother, being a carrier, has one normal X and one affected X. Therefore, the female child will either be a carrier like the mother or inherit two normal X chromosomes, but she will not develop hemophilia.

A Couple Is Planning to Have a Child