Question

A colour blind man marries a woman with normal sight who has no history of colour blindness in her family. His son also marries a woman whose family has no history of color blindness. What is the probability of their grandson being colour blind?

0.25
0.5
1
Nil

Answer 1

The “probability” of their grandson being “colour blind” is 0.50.

Solution:

Though a colour blind man married to woman with normal sight with no background of colour blindness, but as far as the grandsons are concerned, the same depends of the mothers of his sons.

Color blindness is passed by the mothers to their child’s. Hence, daughters of the colour blind man will have gene of colour blindness while his grandsons will have colorblindness if his daughter in law has that gene.

Hence, the probability will be 0.50 of having colour blindness to grandsons of the colour blind man.