Question

Choose the correct option-

A marriage between a colourblind man and a normal woman produces-

• A. 50% carrier daughters and 50% normal daughters
• B. All carrier daughters and normal sons
• C. All carrier offsprings
• D. 50% colourblind sons and 50% normal sons

Answer 1

The correct option is B

All carrier daughters and normal sons

The correct option is B.

Explanation of correct option:

1. Colourblindness is an X-linked chromosomal disorder which reduced the ability to differentiate between colours.
2. It affects males more easily compared to females.
3. Male consist of XY sex chromosome. If the male is colourblind, the one X chromosome produced will be defective. A normal female will produce two normal X chromosomes.
4. The sons born will receive one normal X chromosome from the mother and one normal Y chromosome from the father, thus the sons will be normal. The daughters will receive one normal X chromosome from the mother and one defective X chromosome number from the father, thus all the daughters are carriers.

Final answer: A marriage between a colourblind man and a normal woman produces all carrier daughters and normal sons.