Question

What is the percentage of children being a carrier of haemophilia if their mother is a carrier and their father is a normal man?

• (A) 25%
• (B) 50%
• (C) 75%
• (D) 100%

Answer 1

The Correct Option is A

Explanation:
The percentage of children being a carrier of haemophilia if their mother is a carrier and their father is a normal man is 25% because the gametes formed by mother are X and X^h while the gametes formed by father are X and Y. The genotype of the offspring obtained would be XY, XX, XX^h and X^hY. Thus 50% of children are normal, 25% are carriers of haemophilia and 25% are haemophilic (only son).Hence, the correct option is (A).