Question

A heterozygous carrier of the hemophilia allele in woman marries with a man who is affected with hemophilia. What will be the expected percentage of hemophilia in their female children?

• A. 0%
• B. 25%
• C. 50%
• D. 75%
• E. 100%

Answer 1

The correct option is C 50%

genotype	$X^h$	X
$X^h$	$X^h$ $X^h$	$X^h$X
Y	$X^h$Y	XY

Colour blindness is X-linked recessive disease, which influences the man when present in X chromosome; Y chromosome does not carry any genes. Whereas in females it influences only in homozygous condition. According to the question The woman is a carrier i.e., X$X^h$ and man is affected i.e., $X^h$Y and the cross between the two will result in 50% of the daughters affected according to punnet square. Thus, the correct answer is option C.