Excellent question!
The gene that causes colour blindness is found on the female chromosome. Women have 2 copies of this chromosome and men only have one, so to get colour blindness women would need to inherit 2 copies of this gene whereas men only need to inherit one copy.
Male chromosomes are XY and females are XX. If the colour blindness gene is found on the X chromosome then women have more chance of not getting it as it’s a recessive gene so the dominant non colour blindness gene from one of our parents would mean we weren’t colour blind. But if a male receives the recessive gene from the X from our mums and has a Y from their dads then there’s no dominant X gene to take over. So they will be colour blind.
Comments