Question

Haemophiliac man marries a carrier woman. Percentage of daughters becoming haemophiliac shall be.

• A. $0\%$
• B. $50\%$
• C. $75\%$
• D. $100\%$

Answer 1

Answer: (B)

$50\%$

Haemophilic is X-linked recessive. Let us say Xh represents the affected chromosome. Haemophilic man will have XhY chromosome whereas carrier woman will have XhX chromosome. Their female progeny will be either XhXh (haemophilic) or XhX(carrier). Hence the chances are 50%.

So, the correct answer is '50%'.