Red-green colour blindness is X-linked recessive. A woman with normal colour vision has a father who is red-green colour-blind. The woman has four sons, none of whom are colour-blind. Assume everyone in the family has a normal complement of chromosomes. Each of the next three statements has an explanation for why none of the sons are colour-blind. For each, state if it is possible or not possible, then give the reason for your choice. iii) None of the sons are colour-blind because the mother inactivated the X chromosome with the recessive colour-blindness allele, and that is the one each son inherited.