Question

Boys can inherit the recessive allele (c) that causes red-green colour blindness from their mother, not from their father. The allele for normal red and green vision is C. Which of the following genotypes are possible in men?

c only c only
B. C or c only
C. CC or cc only
D. CC, Cc or cc only

Answer 1

The answer would be b because there is a 50% chance for both.

Answer 2

Well,

If you use the Punnett square chart, you would see that men get 50% and boys 50%

Hence, since both of them are heterogeneous recessive, it would B) C or c only.