ONTOGENESIS (ONTOGENY)
Ontogenesis is a complex of processes of development of an individual (or, individual development). 4 periods can be distinguished in ontogenesis:
- development of an embryo (embryonic development, embryogenesis);
- postembryonic development;
- the period of maturity and reproduction;
- the decline of life finishing in natural death of the individual.
General bases for the ontogenic development of an organism are: growth process ( mitotic cell activity), differentiation of tissues (functional cell activity) and morphogenesis (development of organs and characterictics).