Question

A normal woman whose father was colour blind marries a normal man. There will be ______ chance that her sons would be colour blind.

Options

• 75%

• 50%

• all normal

• all colour blind

Answer 1

A normal woman whose father was colour blind marries a normal man. There will be 50% chance that her sons would be colour blind.

Explanation: The woman must be a carrier because she inherited her father’s affected X chromosome. Each son has a 50% chance of inheriting that X chromosome from her.