Question

a colorblind male marries a normal female. which statement is correct?
a all their daughters will be carriers.
b all their sons will be colorblind.
c half of their daughters will be normal.
d both (a) and (b) are correct.

Explanation:

Colorblindness is an X - linked recessive disorder. Let the normal allele be \(X^C\) and the colorblind allele be \(X^c\). The genotype of the colorblind male is \(X^cY\) and the genotype of the normal female is \(X^CX^C\).

• For daughters: The male can donate \(X^c\) and the female can donate \(X^C\). So, all daughters will have the genotype \(X^CX^c\) (carriers).
• For sons: The male donates \(Y\) and the female donates \(X^C\). So, all sons will have the genotype \(X^CY\) (normal).

Answer:

A. All their daughters will be carriers.