Principles of Inheritance and Variation Question 189
189. Red-green colour blindness in humans is governed by a sex-linked recessive gene. A normal woman whose father was colour blind marries a colour blind man. What proportion of their daughters is expected to be colourblind?
(a) $3 / 4$
(b) $1 / 2$
(c) $1 / 4$
(d) All
Show Answer
Answer : b
Hints & Solution
(b) Normal woman whose father was colour blind would have received the $X$ chromosome from her father $(X^{C} Y) \to$ Progeny $(F_1)$ :
