Cats may have 3 colors at times, they are also known as Calico cats. Cats who have 3 or more colors are female, in other words male cats cant have more than 2 colors(with an exception, discussed later). So why is that? What is the biological reason for this phenomenon?
Like most of the mammals, cats have a XY sex determination system. So the female cats have two X chromosomes and the male cat has a X and a Y chromosome. The X chromosome is the chromosome which determines the color of the cat. So in females there are two chromosomes, so they can have an orange and a non-orange gene on each of the X chromosome.
But this is not possible in male cats as they have only one X chromosome which will either have a orange and a non-orange gene. However, there is one exception to this case where if a male cat has a genetic disease such as Klinefelter syndrome in which the male cat as an extra X chromosome. Klinefelter syndrome cats have XXY chromosome and can have 3 colors.
