Why are male calico cats rare?
Calico cats, with their orange, black and white coloration, are almost always female. So are black and orange tortoiseshells. Why? The answer has to do with genetics. Every cat has 38 pairs of chromosomes; half of the pairs are from the mother, the other half is from the father. Within every chromosome there are thousands of different genes. Every female cat receives one X chromosome from her mother and one X chromosome from her father, while a male receives one X chromosome from his mother and one Y chromosome from his father. Within the X chromosome is a gene for coat color. In calicos and tortoiseshells, one X has the black gene; the other X has the orange gene. White coat color is associated with a completely separate gene. At conception, the kitten is a one-celled organism, which divides until there are millions of cells that make up the final kitten. Each time a cell divides, it passes on its genetic material. For the sex chromosomes, there is a battle for power. This is especial