Editing Cell cycle (section)

{{short description|Series of events and stages that result in cell division}}
{{About|the eukaryotic cell cycle| the prokaryotic cell cycle|fission (biology)| the separation of chromosomes that occurs as part of the cell cycle|mitosis| the academic journal|Cell Cycle (journal){{!}}''Cell Cycle'' (journal)}}
{{see also|Cell division}}
{{Use dmy dates|date=November 2020}}
[[File:Normal Cell Life Cycle.png|thumb|200px|Life cycle of the cell]]
[[File:Wilson1900Fig2.jpg|thumb|200px|Onion (''[[Allium]]'') cells in different phases of the cell cycle. Growth in an '[[organism]]' is carefully controlled by regulating the cell cycle.]]
[[File:Reconstitution in 6 phases, of the changes in cell shape (in red) and nucleoid structure (roughly equivalent to the DNA, in green), during the cell cycle of the bacteria D. radiodurans.webm|thumb|Cell cycle in ''Deinococcus radiodurans'']]
The '''cell cycle''', or '''cell-division cycle''', is the sequential series of events that take place in a [[cell (biology)|cell]] that causes it to divide into two daughter cells. These events include the growth of the cell, duplication of its DNA ([[DNA replication]]) and some of its [[organelle]]s, and subsequently the partitioning of its cytoplasm, chromosomes and other components into two daughter cells in a process called [[cell division]].

In [[eukaryotic cells]] (having a [[cell nucleus]]) including [[animal]], [[plant]], [[fungal]], and [[protist]] cells, the cell cycle is divided into two main stages: [[interphase]], and the [[M phase]] that includes mitosis and cytokinesis.<ref name="Alberts2019">{{cite book | vauthors = Alberts B, Hopkin K, Johnson A, Morgan D, Raff M, Roberts K, Walter P |title=Essential cell biology |date=2019 |publisher=W. W. Norton & Company |location=New York London |isbn=9780393680393 |pages=624–625 |edition=Fifth}}</ref> During interphase, the cell grows, accumulating nutrients needed for mitosis, and replicates its DNA and some of its organelles. During the M phase, the replicated [[Chromosome|chromosomes]], organelles, and cytoplasm separate into two new daughter cells. To ensure the proper replication of cellular components and division, there are control mechanisms known as [[cell cycle checkpoint]]s after each of the key steps of the cycle that determine if the cell can progress to the next phase.

In cells without nuclei the [[prokaryote]]s, [[bacteria]] and [[archaea]], the [[fission (biology)|cell cycle]] is divided into the B, C, and D periods. The B period extends from the end of cell division to the beginning of DNA replication. DNA replication occurs during the C period. The D period refers to the stage between the end of DNA replication and the splitting of the bacterial cell into two daughter cells.<ref name="Wang2009">{{cite journal | vauthors = Wang JD, Levin PA | title = Metabolism, cell growth and the bacterial cell cycle | journal = Nature Reviews. Microbiology | volume = 7 | issue = 11 | pages = 822–827 | date = November 2009 | pmid = 19806155 | pmc = 2887316 | doi = 10.1038/nrmicro2202 }}</ref>

In single-celled organisms, a single cell-division cycle is how the organism reproduces to ensure its survival. In multicellular organisms such as plants and animals, a series of cell-division cycles is how the organism develops from a single-celled [[fertilized egg]] into a mature organism, and is also the process by which [[hair]], [[skin]], [[blood cell]]s, and some [[viscus|internal organs]] are [[Regeneration (biology)|regenerated]] and [[Healing|healed]] (with possible exception of [[nerve]]s; see [[Nerve injury|nerve damage]]). After cell division, each of the daughter cells begin the [[interphase]] of a new cell cycle. Although the various stages of interphase are not usually morphologically distinguishable, each phase of the cell cycle has a distinct set of specialized biochemical processes that prepare the cell for initiation of the cell division.