Question

Choose the correct option-

A man whose father was colourblind marries a woman who had a colourblind mother and father. What percentage of male children of this couple will be colourblind?

• A. 0%
• B. 25%
• C. 50%
• D. 75%

Answer 1

The correct option is C

50%

The correct option is C.

Explanation of correct option

1. Colourblindness is a recessive autosomal genetic disorder linked to the X chromosome.
2. From the question, the man had a colourblind father (genotype- X^CY) and a normal mother (XX) will be normal (XY) as he received a normal X chromosome from his mother.
3. The woman with a colourblind mother ( X^CX^C) and normal father (XY) will be a carrier ( X^CX) as she receives one faulty chromosome from her mother and a normal chromosome from the father.
4. The normal man (XY) and the carrier woman ( X^CX) will produce the following offspring- X^CX (carrier female), XX (normal female), X^CY (colourblind male), and XY (normal male).
5. Since out of 2 possible male offspring, one will be colourblind, the percentage is 50%.

Final answer: 50% of the male offspring produced by this couple will be colourblind.