Ontogenetic variability - variability, reflecting the implementation of regular changes in the course of the individual development of an organism or its cells. It differs from genotypic in that organisms, despite age differences, retain the same genotype , that is, it is non-hereditary, or phenotypic. Of the many mechanisms of occurrence of ontogenetic variability are the following:
- different gene activity
- different activity of endocrine glands,
- a different ratio of growth and differentiation processes at different age periods.
Content
Value
Ontogenetic variability plays an important role in the manifestation of hereditary human diseases. A number of diseases and malformations arise in the embryonic period. Other diseases appear in the postnatal period, more often in childhood, but occasionally in adulthood and even old age. For timely and effective treatment and prevention of hereditary diseases, it is necessary to know the mechanisms of manifestation of ontogenetic variability in individual development and its role in the manifestation of hereditary traits in humans.
Examples
Phenylketonuria - a serious hereditary disease associated with a violation of amino acid metabolism, manifests itself immediately after birth. If timely treatment is not carried out during the first years of life, the child will develop irreversible changes in the central nervous system. After puberty, the body independently cope with the disease.
Literature
O.-Ya.L. Bekish. Medical biology. - Minsk: Urajay, 2000 .-- S. 518. - 152-153 p.
See also
- Genotypic variation
- Phenotypic variation