Question

Hemophilia is X-linked recessive and a sex-linked genetic disease. If a male with hemophilia and a homozygous normal female have a female child, what is the probability that the child will be a carrier for hemophilia?

a. 50%
b. 25%
c. 100%
d. 0%

Answer 1

The answer is 100%. This is because a female has two X chromosomes one from dad and one from mom. And a male has one X chromosome and one Y chromosome. This means that if an affected male crosses with a homozygous normal female, that means that all female daughters will be carriers.