Question

If a couple has a 50% chance of producing an XX chromosome offspring with red-green colourdeficiency, what is the genotype of the couple?For the couple in Q5 (above) what is the percentage chance that their offspring will be XY withnormal colour vision?*note* Please enter numbers only - up to a maximum of 3 digits (0-100)

Answer 1

The genes responsible for the color blindness are on the X chromosome. Hence, this is a case of sex linked inheritance.

If the 50% of the offspring is XX with red-green colour defiency, their genotype will be rg, rg, since red green defiency is a recesive trait. Besides,

1. The XX parent genotype must be rg, rg

2. The XY parent genotype must be rg (as he only have a single X chromosome).

The punnet square in this case will be:

As the punnet square shows, the chance that their offspring will be XY with normal color vision is 0%.