Principle-Of-Inheritance-And-Variation Question 646
Question: 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) [MP PMT 1995]
Options:
A) All colourblind
B) 50% colourblind
C) All normal
D) 25% colourblind
Show Answer
Answer:
Correct Answer: B
Solution:
Infact the girl with normal vision is carrier because her father is colourblind (daughter of colourblind father are either colourblind or carrier) and when she marries a normal man the possibility of their sons being colourblind is 50% because the genotype of parents is X?X and XY, so only half of the possible combinations of XY have the X-linked recessive genes which exhibit the disease.
BETA
