Question

Why is haemophilia generally observed in human males ? Explain the condition under which a human female can be haemophilic.

Answer 1

Haemophilia is caused due to the recessive, gene on X chromosome.

Y has no allele for this / if a male is X^hY then he is haemophilic / if male inherits X^h from the mother he is haemophilic (with the genotype X^hY). 

If female inherits X^hX^h, one from the carrier mother and one from her haemophilic father then she can be haemophilic.