A haploid gamete contains half the number of chromosomes as a diploid cell. In humans, for example, somatic cells contain 46 chromosomes, while gametes (eggs and sperm) contain 23 chromosomes. This reduction in chromosome number occurs during meiosis, the process by which gametes are formed. Meiosis involves two rounds of cell division, and during the first round, the homologous chromosomes pair up and exchange genetic material through a process called crossing-over. The chromosomes then separate and move to opposite poles of the cell, resulting in two daughter cells each with a haploid number of chromosomes. The second round of meiosis is similar to mitosis, and it results in the formation of four haploid gametes.