by Andrew Bucur

Created on: March 30, 2007   Last Updated: May 02, 2007

Cell division is the process by which one cell divides into two cells. The dividing cell is called the parent cell and the cells it divides into are called daughter cells. This process is the biological basis of life. It is the way to regenerate dead or wounded tissue, for example healing of cuts or bruises in animals or broken leaves in plants. In the Amoeba for example, it reproduces a whole organism; most importantly however, it enables cell division from gametes to create the one-celled zygote that sexually reproducing organisms develop from. It is important to realise that an adult human being has approximately 100 000 billion cells, all originating from a single cell, the fertilized egg cell.' Therefore, cell division provides the existence of organisms and the creation of multi-cellular organisms even more so.

The most important aspect of cell division is the maintenance of the original cell's genome. The genomic information stored in chromosomes must be replicated before the actual division can occur. Then, the duplicated genome must be separated in the cells.

Mitosis in higher plants differs from mitosis in animal cells mainly in two stages: preprophase and cytokinesis.

Only in the plant cells, the prophase stage is preceded by a preprophase stage. This is because of the highly vacuolated cells in which the nucleus has to reach to reach the center of the cell before the division process can initiate. The cells of higher plants (e.g. flowering plants) lack centrioles and spindle microtubules go on the surface of the nuclear envelope during prophase.

In animal cells, a pinch containing a contractile ring develops where the metaphase plated was before, pinching off the separated nuclei. Both in animal and plant cells, cell division is as well driven by vesicles derived from the Golgi apparatus they move along microtubules to the center of the cell. In plant cells, this structure develops into a cell wall thus separating the two nuclei. Cytokinesis is the final phase of cell division; there are now two separate cells and the original cell has stopped dividing.

Mitosis and Meiosis Compared (Head to Head):

Meiosis

Interphase - begins with a diploid cell
Prophase - four chromosomes combine to form two tetrads
& the chromosomes in the tetrad cross over each other, allowing them to exchange genetic material
Metaphase - the two tetrads line up in the center
Anaphase - the two tetrads split up into four chromosomes which go to both poles
Telophase - the two sets of

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