ABSTRACT
Unlike somatic cells, the mature germ cells, or gametes, are haploid: they have only one copy of each chromosome, and either an X or a Y chromosome. The 23 chromosomes in the germ cell form a pronucleus. Following fertilization, fusion of the pronuclei from the sperm and the ovum re-establish diploidy, and thus result in a somatic cell with a full complement of 46 chromosomes.
