In cats, the autosomal recessive genes for blue eyes and deafness are located in the same autosome.

In cats, the autosomal recessive genes for blue eyes and deafness are located in the same autosome. What offspring can be expected from crossing a hearing orange-eyed cat with a blue-eyed deaf cat if the mother of the cat is known to have blue eyes and the father was deaf?

Let’s designate the gene for deafness in cats as g, then the gene for normal hearing will be G.

Let’s designate the gene for blue eyes in cats as M, then the gene for orange eyes will be designated as m.

A blue-eyed deaf cat will be written ggmm, it will produce gm sperm.

The mother of the cat had blue eyes – mm, therefore, she could transmit to the cat only one recessive gene m.

The cat’s father was deaf – gg, therefore, he could only transmit the deafness gene g to the cat.

The cat has orange eyes and normal hearing and is therefore diheterozygous – GgMm. It produces two types of germ cells GM and gm, because the genes for deafness and blue-eyed, according to the condition, are linked.

The offspring of this pair of individuals will be represented by the following options:

kittens with orange eyes and normal hearing (GgMm) – 25%;

kittens with blue eyes and deaf (ggmm) – 50%.