In sexually reproducing organisms, one set of chromosomes is in the female gamete or egg cell and one set is in the sperm cell. This amount is the haploid amount and was produced by the process of meiosis in the gonads. After the egg cell is fertilized by the sperm cell, there is a diploid set of chromosomes in the zygote. Therefore, in diploid organisms, there will be two copies of each chromosome. When they are paired up in a karyotype, attention is paid to the length, centromere position and staining pattern. These pairs are known as homologous chromosomes. The first 22 pairs or autosomes are similar in length. That doesn't necessarily hold true for the sex chromosomes where the X is much larger than the Y chromosome in males. Females have a homologous pair of sex chromosomes, known as XX.