Saturday, December 18, 2010

HAPLOID CELL

Another type of cell division is known as meiosis. Meiosis involves the division of a cell into four daughter cells. It takes place only in reproductive organs (eg: in the testes and ovaries of animals and in the anthers and ovules of plants).

The purpose of meiosis is to produce gametes or reproductive cells so that sexual reproduction in organisms can occur.

Unlike those produced through mitosis, these daughter cells are usually not genetically identical to their parent cells. The chromosomes in each daughter cell are half the number found in the parent cell.

While cell division occurs once during mitosis, cell division occurs twice during meiosis. Meiosis I is followed by Meiosis II.

In Meiosis I, the cell divides into two daughter cells, whose number of chromosomes is halved. In Meiosis II, each of the two daughter cells divides into another two daughter cells, resulting in four haploid daughter cells (with the same halved number of the original chromosomes).

Shown in the following diagram are the basic differences between mitosis and meiosis.

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