main provisions of cell theory is the basis for understanding the laws of the origin and existence of living organisms, consisting of basic structural units.This generalization of the biological proof that life exists only in the cage, as well as the fact that every "living cell" is an entire system that can exist independently.
main provisions of cell theory formulated by M. Schleiden and T. Schwann and supplemented R. Virchow.Before you make conclusions and formulate the postulates of this theory, the specialists worked the works of many of his predecessors.So, in 1665 Robert Hooke first saw on the tube formation, called "cells".It was then described cellular structure of many plants.Later A. Leeuwenhoek described unicellular.In the nineteenth century.improve the design of the microscope leads to a broadening of the concept of the structure of organisms, the concept of the living tissues.T. Schwann conducting a comparative analysis of the smallest structural unit of the representatives of flora and fauna, and in Schleiden the book "Materials on phytogenesis."
main provisions of cell theory developed by Schleiden and Schwann:
- all flora and fauna are composed of basic structural units.
- growth and development of plant and animal organisms occur due to the emergence of new "living cells."
This structure is the smallest unit of the living, and the body - is their combination.
R.Virhov then added a very important point that every structural unit is derived from their own kind.This work was edited and summarized many times.Now the main provisions of the modern theory of the cell are as follows:
- cell is an elementary unit of living things.
- smallest structural unit of all living things are homologous composition and metabolic processes of life.
- cells multiply by dividing the parent.
- All elementary living units have the same principle, that is,They totipotent.
- In multicellular organisms, the smallest unit of living combined with each other according to the functions that are performed while forming more complex structures (tissue, organs and organ systems).
- Each "living cell" is an open system, which is able to self-regulate the updating, reproducing and maintain homeostasis.
in recent years (after a number of scientific discoveries) this theory expand, adding new information.However, it is not completely systematized, so some of its postulates are treated fairly arbitrary.Consider the most common additional provisions cell theory:
- smallest structural units of pre-nuclear and nuclear organisms is not fully its composition and structure are identical to each other.
- continuous transmission of genetic information also applies to some organelles (chloroplasts, mitochondria, chromosomes, genes) "living cell".
- elementary unit of living though totipotent, however, the work of their genes are different.That leads to their differentiation.
- multicellular is a complex system, the functioning of which is carried out by chemical factors, humoral and neural regulation.
Thus, the main provisions of cell biological theories are generally accepted generalization that proves the principle of unity of structure, the existence and development of all living beings having a cellular structure.
