A woman with normal vision, whose father was colour blind, marries a colour blind man. What will be the possible phenotypes and genotypes of their offspring? (a) Colour blind son and colour blind daughter. (b) Normal vision son and carrier daughter. (c) Normal vision son and homozygous normal vision daughter. (d) Colour blind son and homozygous normal vision daughter. Choose the most appropriate answer from the optio

Step-by-step solution

Colour blindness is an X-linked recessive trait. Let X^C be the normal allele and X^c be the colour blind allele. The woman has normal vision, but her father was colour blind ( X^c Y ). Thus, she inherited the X^c allele from her father, making her genotype X^C X^c (carrier). The man is colour blind, so his genotype is X^c Y . The cross is X^C X^c X^c Y . The possible genotypes and phenotypes of the offspring are: 1. X^C X^c : Carrier daughter with normal vision 2. X^c X^c : Colour blind daughter 3. X^C Y : Normal