CBSE Class 12-science Answered

Colourblindness is an X-linked recessive trait caused due to the defective allele on the X chromosome.

In this problem,

Since the father is colourblind, his genotype would be X^cY.

Although the woman has colourblind father, her vision is normal. This implies that she is a carrier of the trait. Therefore, her genotype would be.

This carrier woman marries a man with a normal vision.

From the above Punnett square, we can deduce that 50% of the daughter are carriers while 50% are normal. 50% of the sons are colourblind while 50% are normal.