Why do sons of haemophilic father never suffer from this trait?
Solution:
Haemophilia is an X-linked recessive trait. There is no chance that a son will be haemophilic if his father is haemophilic because a father passes only the Y chromosome to a boy and the X chromosome to a girl. Since Y gamete does not hold this trait, he will not be affected by the disease.
Haemophilia is an X-linked recessive trait. There is no chance that a son will be haemophilic if his father is haemophilic because a father passes only the Y chromosome to a boy and the X chromosome to a girl. Since Y gamete does not hold this trait, he will not be affected by the disease.