Q. If a haemophilic man marries a normal lady, the of fsprings will be
Chhattisgarh PMTChhattisgarh PMT 2006
Solution:
Haemophilia is a sex-linked recessive disease/disorder. In female, haemophilia appears when both the sex chromosomes carry its recessive gene, ie, $ {{\text{X}}^{\text{h}}}{{\text{X}}^{\text{h}}}\text{.} $ Female, dies after birth, but if it carrier ( $ \text{X}{{\text{X}}^{\text{h}}} $ ) it does not die. In male, $ {{\text{X}}^{\text{h}}}\text{Y} $ is haemophilia because males are hemizygous. Therefore according to this Normal woman Haemophilic man
(Carrier (Normal (Carrier (Normal daughter) son) daughter) son) So, all daughters will be carriers (ie, normal) and sons will be normal. Thus, all offsprings will be normal.
