Haemophilia is

A couple whose sons are colourblind with $AB$ blood group, identify the parents from the following..

A normal­visioned man whose father was colour­ blind, marries a woman whose father was also colour­blind. They have their first child as a daughter. What are the chances that this child would be colour­ blind ?

Which of the following is a genetic disease

Gene for colourblindness is located on

The most striking example of point mutation is found in a disease called