Trish Anderson of Ragpride Ragdolls cat has 19 pairs of chromosomes. The xx pattern gives us a female kitten and the xy pattern gives us a male kitten. Several interesting points follow from this.
Males control the sex of the offspring.
Girls have more genes than boys. Because the male has one arm missing off his x chromosome to make a y shape, the female carries more genetic material than the male. The arm causes the female to be a female, whereas the default is the male. There are other genes on this arm apart from the genes causing the sexual characteristics of the female. These other genes are said to be sex linked because they cannot be carried by the male who is lacking this genetic material.