Cell Division

Cell division is the process by which one parent cell gives rise to two (or, in meiosis, four) daughter cells, and it is the mechanical culmination of everything the cell cycle has been building towards. Three distinct patterns of cell division are recognised. Amitosis is a simple, direct form of division seen in a few specialised or degenerating cell types, in which the nucleus and cytoplasm each pinch in two without ever forming a spindle. Mitosis is the far more general pattern seen in growing tissues, replaced cells, and asexually reproducing organisms; because the daughter cells end up with the same chromosome number as the parent, mitosis is also called equational division, and in plants it is concentrated in actively growing meristematic tissue such as shoot and root tips. Meiosis is the specialised division restricted to cells destined to become gametes (or, in flowering plants, spores); because it halves the chromosome number, it is also called reductional division. The rest of this …