Genes for hair color in cats are located on the X chromosome. Red color is determined by Xb, and black

Genes for hair color in cats are located on the X chromosome. Red color is determined by Xb, and black – XB, heterozygous individuals have a tortoiseshell color. From a red cat and a black cat, two tortie and two black kittens were born. Determine the genotypes of the parents, offspring and the possible sex of the kittens.

The genotype of the cat is XbY, the b gene (red color) is located on its X chromosome.
The genotype of the cat is XBXB (black color). She is homozygous.

Male kittens (XY) receive an X chromosome from the mother and a Y chromosome from the father. The cat is homozygous, so all her kittens will get the B gene. All black kittens from such a cat are males (XBY).

Female kittens (XX) receive one X chromosome from each parent. From a black homozygous mother – XB, from a red-haired father – Xb.
All female kittens from this pair are heterozygotes (XbXB) tortoiseshell.