Question

If a colourblind man marries a woman whose father is colourblind. What will be the genotype of their offsprings?

• A. All sons are cololurblind.
• B. 50% daughters are colourblind.
• C. All daughters are normal.
• D. All daughters are colourblind.

Answer 1

The correct option is B 50% daughters are colourblind.

Since the man is colourblind, his genotype is X^cY.

Since the father of the woman is colourblind, therefore, the woman will be carrier for colourblindness and her genotype will be X^cX.

The cross can be represented as shown in the figure.

Hence, out of two daughters, one will be colourblind and the other one will be a carrier i.e. 50% of the daughters are colourblind.

So, the correct answer is '50% daughters are colourblind'.