A haploid cell has half the chromosome amount as a diploid cell. Haploid cells are gametes, also known as sperm or egg cells. Diploid cells are also called somatic cells. These are the cells that make up the body of an organism. In sexually reproducing organisms, the gametes each supply half the chromosome complement to the offspring. This preserves the species number of chromosomes. For example, if a human body cell has 46 chromosomes and is diploid, a human egg or sperm has 23 chromosomes in each and is considered to be haploid. At fertilization, when the sperm nucleus joins the egg nucleus, the full diploid complement of chromosomes is restored.