Cytokinesis is the final process in eukaryotic cell division, which divides the cytoplasm, organelles, and cellular membrane. It typically occurs at the end of mitosis, after telophase, but the two are independent processes. In most animals, cytokinesis begins sometime in late anaphase or early telophase, to ensure the chromosomes have been completely segregated. The movements can be seen in the cell are caused by the same spindle network that was responsible for the separation of the chromosomes. Parts of the spindle responsible for moving chromosomes break down in late cell division, to be used in restructuring the two new cells.

Cytokinesis

Cells can divide evenly, known as symmetrical cytokinesis, or one of the cells can retain a majority of the cytoplasm. During male meiosis in humans, for example, all 4 cells at the end of meiosis have the same size, and relative number of organelles. This process of spermatogenesis produces millions of small, but mostly equal sperm. Human oogenesis, on the other hand, divides through asymmetrical cytokinesis. This produces one very large cell, and 3 polar bodies. The smaller polar bodies do not become eggs. In this way, fewer eggs are produced, but they are much larger cells. Some cells, in humans and other species, do not undergo cytokinesis after mitosis, and form large multi-nucleated cells.

In animals and plants, the occurrence is different. In animals, the cell divided by making a furrow and the central part of the spindle gets changed into a fibrous structure mid-body. The furrow deepens medically and gets divided into two daughter cells from a single parent cell. During division, the midbody of the cell gets compressed and smaller and finally disappears forming the two fully formed cells. This type of cytokinesis is known as cleavage cytokinesis.

In plants, cytokinesis takes place by cell wall formation. The equator gets lined up with the small vesicles produced by the Golgi apparatus and the membranes of vesicles fuse to form a plasma membrane. With the formation of the cell plate, the spindle disappeared. The cell plate in the plant is made up of cellulose, hemicellulose and pectin and after the division, this deposit on the middle lamella side and helps in the formation of the primary cell wall.

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By Team Learning Mantras