Individual development of organisms - a setbiological processes that cause the growth and change of cells throughout the entire period of their existence. The common scientific name is ontogeny. Its main task is to observe, identify the main stages and characteristics of each period, identify patterns, and analyze the changes and identify the factors that these changes can cause.
Individual development of the organism is inherent not only to man, but to all living beings and plants. The main stages of development are:
To consider the individual development of the bodyplants in this small article, we will not, but we will dwell on the development of representatives of the animal world closer to man. Stages of development, as already mentioned, do not change in a person and correspond to those mentioned above.
Human gametogenesis consists of twocomponents: spermatogenesis (maturation of male sex cells - spermatozoa) and oogenesis (maturation of female reproductive cells - oocytes). Fertilization is possible only under condition of mature sexual cells in male and female individuals. When pathologies arise in fertilization, organisms can be formed - chimeras, some of which are quite viable.
Human embryogenesis is one of the most important stages. It is divided into the initial stage (0 - 1 week after fertilization), actually the embryonic stage (2 - 8 weeks) and the fetal or fetal stage (9 weeks - birth). It is during this period that vitally important organs are formed, the body is made out, genetic or other pathologies can manifest themselves.
Individual development of the organism in postnatalthe period consists in the further development of organs, the increase in size and mass, the acquisition of new mental functions, the alteration of the motor activity and the development of its new species.