Question

What is the cause of haemophilia and colour blindness?

Answer 1

Cause of Haemophilia - Haemophilia is an X-linked inherited disease. Homozygosity for recessive haemophilia gene is must to be seen in a female while a single affected X chromosome makes the male a haemophilia victim.
Cause of Colour Blindness - Colour blindness is the effect of a recessive gene. In case of female, both the X chromosomes must have the recessive gene but as males have only one X chromosome, just a single affected chromosome causes colour blindness.