Microbiology => Fission
Fission, in biology, type of asexual reproduction characterized by division of the body into two or more parts, each of which develops into a complete individual. Two-part, or binary, fission may be identical with cell division , or it may involve a reorganization of the cytoplasm and a building up of new cellular structures. Fission is common among single-celled organisms but is rare in multicellular organisms, as it requires a regeneration of specialized parts in each of the daughter individuals. Binary fission in microorganisms may be transverse (occur across the width of the organism), as in the paramecium, or it may be longitudinal (occur along the length of the organism), as in the euglena, a colonial flagellate.
Multiple fission may consist of several successive binary fissions within a sheath, as in Sporozoa, a class of parasitic protozoans; or the nucleus may divide repeatedly, and the cytoplasm subsequently divide into as many parts as there are nuclei, as in the malarial protozoan. Some worms (the planarians and certain annelids) sometimes reproduce by fission.