Cell Division





What is cell division?

All living body are made by cell. The life of an organism starts from a single cell. Starting from a single cell it divides and re-divides to form multicellular organism. And the multicellular organism produces an embryo or larva. Ultimately the embryo or larva develops into a adult organism via a controlled cell division and differentiation. In the year 1850 cell division was discovered by scientist Von Mohl and about in the same time it was discovered by another scientist Virchow. In this same year scientist Hofmeister observed the division of and nucleus into daughter nuclei followed by the division of the cytoplasm of the cell.



The cell division is considered as the fundamental characteristic of an organism and as a result of which size each of an organism increases. But immediately before the cell division, the cell shows anabolism and accumulation of cytoplasm at a maximum rate. Cell division is responsible for the continuity of the life processes. Mainly two types of cell division occur, those are mitosis and meiosis. Mitosis is occurring in the somatic cells and meiosis occurring in the germ cells. The nerve cell and matured Red Blood Corpuscles (RBC) do not divide. After meiosis the gametes are formed, but after attaining maturity they do not divide.

What are the causes of cell division?

Mainly the three causes of cell division are as follows:

i)Increase in the rate of metabolism induces increase in volume of cytoplasm causes auxetic growth, which induces cell division and initiates for the multiplicative growth.
ii) The doubling of DNA within cell initiates nuclear division and ultimately resulting in the division of cytoplasm.
iii) Damage or any wound in the body of an organism causes increase in the rate of cell division because the process of healing of wound requires it.
Importance of cell division: -
For a living organism the cell division has great importance throughout its life span, those are:
i) Production of new individual through reproduction.
ii) Regeneration of damaged tissue.
iii) Initiating growth and differentiation.
iv) Development of different organs.
v) Modification in organs causing adaptation and permanent changes in adaptive features will induce evolution.

Types of cell division:

i) Direct cell division or Amitosis.
ii) Indirect cell division or Mitosis.
iii) Reductional division or Meiosis .



Definition of cell division: -

The cell division is a fundamental and an active biological process by which a cell produces its own replica having similar structural and physiological properties and brings upon continuity of life.

Definition of Amitosis: -

The cell division showing simple nuclear cleavage without the formation of spindle fibres is known as direct cell division or amitosis.

Definition of Mitosis: -

The cell division in which the parent cell divides once giving rise to two identical daughter cells with same chromosome number with similar forms and characteristic feature is called indirect cell division or Mitosis.

Definition of Meiosis:

Meiosis is a complex cell division process in which the diploid number of chromosomes of the mother cell is reduced to haploid number of chromosomes in the four daughter cells.