Cages breed by division – creation two affiliated of one maternal. Depending on type of cages, this reproduction can happen towers in the ways – by means of a mitosis, meiosis or amitotic division.
Mitosis
The mitosis is the most widespread way of cell fission. After a mitosis both daughter cells are the exact copy parental. The longest phase of a mitosis is a pro-phase. During it chromosomes in which information on a cage is concluded spiralizutsya and thickened. In a phase of rest of a chromosome are in a kernel, however in a pro-phase the kernels and a nuclear cover are dissolved, and now hereditary material disperses on all cytoplasm. Centrioli disperse to poles of a cage and form a division spindle.
After professional elements there comes the metaphase. During this period of a chromosome are located in such a way that their centromer are built exactly on the equator of a cage. Division spindle threads are attached to centromer.
During the following stage – an anaphase centromer double. Hromatida of which chromosomes consist separate from each other, and division spindle threads, being reduced, begin to bring up them to poles. During a telofaza, cytoplasm and other organelles shares. Chromosomes are untwisted and again form a kernel, and the longitudinal banner divides a maternal cage into two affiliated.
Doubling of genetic material happens during an interfaza – an interval between divisions when the cage is in rest.
Meiosis
Meiosis is a division during which a set of chromosomes decreases twice. Meiotic division meets at gametes of animals and plants. Meiosis passes through two cycles which are, at first sight, similar to a mitosis, however there are also essential distinctions. In time professional elements of I which in a mitosis is much more long, than in meiosis chromosomes connect and exchange genetic information among themselves. The anaphase of the I meiosis is characterized by the fact that during it centromer do not share, and by means of a division spindle to a pole of a cage only one of homologous chromosomes is delivered. After the first division the second as a result of which four cages are formed at once begins, each of which possesses an unary set of chromosomes. It will become double again after there is a fertilization.
At some simplest organisms the meiosis proceeds in other way, keeping within only one cycle of division.
Amitotic division
Amitotic division – the unusual occurrence which is usually proceeding in the cages which are growing old or doomed to death, usually being the emergency means. During amitotic division the division spindle is not formed. The cage shares way of a simple banner, and hereditary material is distributed between daughter cells in a random way.