Cell cycle, mitosis, meiosis
Cell cycle

Human cells contain 23 pairs of chromosomes: 22 pairs are homologous (autosomes) and one pair is sexual (gonosomes). Sexual chromosomes in the female sex have two X-chromosomes; in the male they have one X and one Y-chromosome. The 23 pairs of chromosomes form a diploid chromosome set (2n, where n is the number of sets of chromosomes); one set is of maternal origin and the other of paternal origin. The karyotype in the female is written as 46,XX, and in the male as 46,XY. Meiosis (formation of the gametes) causes the pairs of chromosomes to separate. The result is a haploid chromosome set (1n).