Ontogenesis

The development through successive transformations of an individual organism in a lifetime is referred to as ontogeny. It consists of growth and differentiation morphologically, physiologically and biochemically. During this process the hereditary information contained in each cell of the organism is realized. The interaction of the many influencing factors (including environmental conditions and reactions between cells and tissues) determines the complex ontogenetic patterns which constitute the program of ontogeny, the three main processes being growth, development and aging. Some sources quote the perinatal phase being experienced as a complete lifecycle before birth.