Calvin's father has red-green colour blindness, but his mother does not carry the allele for this trait.What can you predict about the colour vision of Calvin and his three sisters?

Question

Quizplus · Accepted Answer

Calvin's father is colour blind, which means he has the recessive allele for red-green colour blindness. His mother does not carry the allele, which means she has two dominant alleles for normal colour vision. Calvin will inherit one allele from each parent, so he will have one dominant allele for normal colour vision and one recessive allele for colour blindness. This means that Calvin will have normal colour vision, but he will be a carrier for the trait. Calvin's sisters will all inherit one dominant allele for normal colour vision from their mother, and one allele from their father. Since their father has only the recessive allele, all of Calvin's sisters will have normal colour vision, but they will all be carriers for the trait.

Calvin's Father Has Red-Green Colour Blindness, but His Mother Does