Question

If a colour blind woman marries a normal visioned man, their sons will be :

• A. All normal visioned
• B. One half colour blind and one half normal
• C. Three fourths colour blind and one fourth normal
• D. All colour blind

Answer 1

The correct option is D All colour blind

Colour blindness in humans is an X-linked recessive inheritance disorder.
Therefore, if a woman is colour blind it means that she is carrying the mutated gene on both the X chromosomes.
If a woman marries a man, then her sons will receive the X chromosome from the mother.
If the mother turns out to be colour blind, then the sons will receive the X chromosome with the mutated gene and hence are affected by colourblindness.