question_answer

A girl of normal vision whose father was colourblind marries a man of normal vision whose father was also colourblind. Their sons would be (of total number of sons).

A)  all colourblind                  

B)  50% colourblind

C)  all normal                          

D)  25% colourblind

Correct Answer: B

Solution :

A normal vision woman has a colour blind father so, the girl is carrier (daughters of colourblind   father are either colourblind or carrier) marries a normal man whose father is also colourblind, so their ratio of sons would be Carrier woman Normal man \[\therefore \]50% of sons would colourblind and 50% of sons would normal vision.