19.A haemophilic male marries a homozygous normal female. What is the percentage of their son to become hemophilic? A. 0% B. 50% C. 75% D. 25%
Option A Here Man is hemophilic which means his X chromosome is defective, and the mother is normal, so in the son X chromosome definitely comes from mother, but not from father so the answer is 0%.
