Binary+fission

=Binary fission=

**Binary fission** is the process of asexual cell division in prokaryotes and some eukaryotic organelles, such as mitochondria and peroxisomes. Mitosis is not possible in prokaryotes because of the absence of a nucleus and linear chromosomes with a defined centromere region.

The process itself involves DNA replication, from a single origin of replication, followed by attachment of each of the parent and replicated DNA molecules to a separate part of the cell membrane. The cell then elongates, causing the chromosomes to separate, and the membrane invaginates, pinching the cells off from one another in a similar fashion to eukaryotic cytokinesis. Division is directed by a bacterial protein called FtsZ, a homologue of tubulin, the protein that polymerises to form eukaryotic microtubules (which themselves are involved in eukaryotic cell division).

Although binary fission of eukaryotic organelles is well-understood, exactly how the organelles are allotted to each daughter cell of cytokinesis remains unclear.