Polyploid
A polyploid cell (of the Greek : πολλαπλόν - multiple) of a organization contains more than two copies (Ploïdie) of its Chromosome S. the polyploid types are called triploid (3x), tetraploid (4x), pentaploid (5x), hexaploïde (6x) etc
Polyploidy at the vegetable cells can be the consequences of a process of endoreduplication. It is about an alternative of the traditional cellular cycle where the DNA is duplicated without division of the cell. The mitosis does not take place and the cellular cycle is re-initialized. Cells where this process with place has increasingly raised ploïdies since the DNA is duplicated in loop. Moreover sizes of the cores being multiplied by ten, the volume of the cells follows this tendency. This mechanism could play a part in the ways of adaptation of the plants to the abiotic stresses. The ploïdies must be higher or equal to 4C to raise of the endoreduplication.
The ploïdie of the cells can be given expressed as a percentage cores in 2C, 4C, 8C, 16C, and 32C for a fabric sample given with the technique of cytometry of flows.
Certain mutants of Arabidopsis thaliana making endoreduplication more or less were described in scientific articles.
See too
External bond
- Polyploidy one Kimball' S Biology Pages
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