Class 12 NEET Biology Principles of Inheritance and Variation Questions Part 2

When a colour blind man (X∘Y) marries a normal woman (XX), all of their daughters are carriers and all of their sons are normal, as shown in following figure: When the carrier daughter (XXc) is married to a normal man, the probability of their son being colour blind is 0.25 , as shown in following figure:From above crosses, it is clear that the probability of occurrence of colour blindness in the grandson of a colour blind man and a normal woman is 0.25 .