The term
somatic is often used in biology to refer to the cells of the body in contrast to the germ line cells which usually give rise to the
gametes (
ovum or
sperm). These somatic cells are
diploid containing two copies of each
chromosome, whereas the germ cells are
haploid as they only contain one copy of each chromosome. Although under normal circumstances all somatic cells in an organism contain identical
DNA, they develop a variety of tissue-specific characteristics. This process is called
differentiation, through
epigenetic and regulatory alterations. The grouping of like cells and tissues creates the foundation for organs.