During cytokinesis, a living cell divides into two, according to Biology Reference. The process occurs at the end of the cell cycle and signals the beginning of new cell generation.
Cytokinesis is the final stage of the cell cycle in which cytoplasm, the material within the living cell, divides into two daughter cells, according to Biology Reference. The contractile ring is the structure that makes cytokinesis happen. It assembles underneath the plasma membrane that surrounds the living cell and contracts, in order to constrict the cell into two. The first visible change is a pucker, or cleavage furrow, appearing suddenly on the surface of a cell. This pucker deepens rapidly and spreads until it divides the cell completely into two, states the National Center for Biotechnology Information.
Cytokinesis starts in anaphase, which is the stage of mitosis during which two sets of chromosomes separate and move away from one another. The process ends in telophase, which is the final stage of mitosis in which two sets of separated chromosomes decondense before their enclosure within nuclear envelopes, according to the National Center for Biotechnology Information.
Cytokinesis must occur at the right time because if it is too early, it disrupts the path of separating chromosomes. It must also occur in the right location, otherwise each daughter cell does not receive a full set of chromosomes.