A normal-visioned man whose father was colour. Blind, marries a woman whose father was also colour blind. They have their first child as a daughter. What are the chance that this child would be colour blind?

Options

(a) 100%
(b) 0%
(c) 25%
(d) 50%

Correct Answer:

0%

Explanation:

If a normal visioned man marries a woman whose father was also colourblind. Then his wife would be carried of this disease if her mother was normal. This trait passed in to children but daughters produce by this cople are carrier not the colourblind. 50% of sons would be colourblind.