Editing Cell division (section)

{{Short description|Biological process}}
{{distinguish|cellular differentiation}}

[[Image:Three cell growth types.svg|thumb|300px|right|Cell division in prokaryotes ([[binary fission]]) and eukaryotes ([[mitosis]] and [[meiosis]]). The thick lines are chromosomes, and the thin blue lines are fibers pulling on the chromosomes and pushing the ends of the cell apart.]]
[[File:Cell Cycle 2.svg|thumb|'''The [[cell cycle]] in eukaryotes:''' I = Interphase, M = Mitosis, G<sub>0</sub> = Gap 0, G<sub>1</sub> = Gap 1, G<sub>2</sub> = Gap 2, S = Synthesis, G<sub>3</sub> = Gap 3.]]
'''Cell division''' is the process by which a parent [[cell (biology)|cell]] divides into two daughter cells.<ref>{{Cite book|title=A dictionary of biology|date=2020 | vauthors = Martin EA, Hine R | publisher = Oxford University Press |isbn=9780199204625|edition=6th|location=Oxford|oclc=176818780}}</ref> Cell division usually occurs as part of a larger [[cell cycle]] in which the cell grows and replicates its chromosome(s) before dividing.  In [[eukaryote]]s, there are two distinct types of cell division: a vegetative division ([[mitosis]]), producing daughter cells genetically identical to the parent cell, and a cell division that produces [[Haploidisation|haploid]] [[gamete]]s for sexual reproduction ([[meiosis]]), reducing the number of [[chromosome]]s from two of each type in the [[diploid]] parent cell to one of each type in the daughter cells.<ref name=":0">{{Cite book|title=Introduction to genetic analysis|date=2012| publisher=W.H. Freeman and Co.| vauthors = Griffiths AJ | isbn=9781429229432 |edition=10th |location=New York |oclc=698085201 }}</ref> Mitosis is a part of the [[cell cycle]], in which, replicated chromosomes are separated into two new [[Cell nucleus|nuclei]]. Cell division gives rise to genetically identical cells in which the total number of chromosomes is maintained. In general, mitosis (division of the nucleus) is preceded by the S stage of [[interphase]] (during which the [[DNA replication]] occurs) and is followed by [[telophase]] and [[cytokinesis]]; which divides the [[cytoplasm]], [[organelle]]s, and [[cell membrane]] of one cell into two new [[Cell (biology)|cells]] containing roughly equal shares of these cellular components. The different stages of mitosis all together define the [[M phase]] of an animal [[cell cycle]]—the division of the mother cell into two genetically identical daughter cells.<ref>{{Cite web|title=10.2 The Cell Cycle – Biology 2e {{!}} OpenStax|url=https://openstax.org/books/biology-2e/pages/10-2-the-cell-cycle|access-date=2020-11-24|website=openstax.org|date=28 March 2018 |language=en}}</ref> 

To ensure proper progression through the cell cycle, DNA damage is detected and repaired at various checkpoints throughout the cycle. These checkpoints can halt progression through the cell cycle by inhibiting certain [[Cyclin-dependent kinase complex|cyclin-CDK complexes]].  Meiosis undergoes two divisions resulting in four haploid daughter cells. [[Homologous chromosome]]s are separated in the first division of meiosis, such that each daughter cell has one copy of each chromosome. These chromosomes have already been replicated and have two sister chromatids which are then separated during the second division of meiosis.<ref>{{Citation |last=Gilbert |first=Scott F. |title=Meiosis |date=2000 |url=https://www.ncbi.nlm.nih.gov/books/NBK10019/ |work=Developmental Biology. 6th edition |access-date=2023-09-08 |publisher=Sinauer Associates |language=en}}</ref> Both of these cell division cycles are used in the process of sexual reproduction at some point in their life cycle. Both are believed to be present in the last eukaryotic common ancestor.

[[Prokaryote]]s ([[bacteria]] and [[archaea]]) usually undergo a vegetative cell division known as [[binary fission]], where their genetic material is segregated equally into two daughter cells, but there are alternative manners of division, such as [[budding]], that have been observed. All cell divisions, regardless of organism, are preceded by a single round of DNA replication.

For simple [[Unicellular organism|unicellular]] [[microorganism]]s such as the [[amoeba]], one cell division is equivalent to [[reproduction]] – an entire new [[organism]] is created. On a larger scale, mitotic cell division can create [[Offspring|progeny]] from [[multicellular organism]]s, such as [[plant]]s that grow from cuttings. Mitotic cell division enables [[Sexual reproduction|sexually reproducing]] organisms to develop from the one-celled [[zygote]], which itself is produced by fusion of two [[gamete]]s, each having been produced by meiotic cell division.<ref name=":1">{{Cite book |last=Gilbert|first=Scott F. | name-list-style = vanc |date=2000|chapter=Spermatogenesis|chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK10095/|title=Developmental Biology |publisher=Sinauer Associates | edition = 6th }}</ref><ref name=":2">{{Cite book|last=Gilbert|first=Scott F. | name-list-style = vanc |date=2000|chapter=Oogenesis|chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK10008/|title=Developmental Biology |publisher=Sinauer Associates |edition=6th}}</ref> After growth from the zygote to the adult, cell division by mitosis allows for continual construction and repair of the organism.<ref>{{Cite book|title=Cells : building blocks of life|date=1997|publisher=Prentice-Hall|author=Maton, Anthea|isbn=978-0134234762|edition=3rd|location=Upper Saddle River, N.J.|pages=[https://archive.org/details/cellsbuildingblo00mato/page/70 70–74]|oclc=37049921|url-access=registration|url=https://archive.org/details/cellsbuildingblo00mato/page/70}}</ref> The human body experiences about 10 [[Names of large numbers#Standard dictionary numbers|quadrillion]] cell divisions in a [[Maximum life span|lifetime]].<ref>{{Cite magazine|url=https://harpers.org/archive/2008/04/contagious-cancer/|title=Contagious Cancer|last=Quammen|first=David | name-list-style = vanc |date= April 2008 |magazine=Harper's Magazine|access-date=2019-04-14|issn=0017-789X}}</ref>

The primary concern of cell division is the maintenance of the original cell's [[genome]]. Before division can occur, the genomic information that is stored in chromosomes must be replicated, and the duplicated genome must be cleanly divided  between progeny cells.<ref>{{Cite book|title=Cell division : theory, variants, and degradation | date=2010|url=https://www.worldcat.org/oclc/929650897|publisher=Nova Science Publishers|author1=Golitsin, Yuri N. |author2=Krylov, Mikhail C. C.|isbn=9781611225938|location=New York|pages=137|oclc=669515286}}</ref> A great deal of [[Cytoskeleton|cellular infrastructure]] is involved in ensuring consistency of genomic information among generations.<ref>{{Cite journal|last1=Fletcher|first1=Daniel A.|last2=Mullins|first2=R. Dyche|date=28 January 2010|title=Cell mechanics and the cytoskeleton|journal=Nature|volume=463|issue=7280|pages=485–492|doi=10.1038/nature08908|issn=0028-0836|pmc=2851742|pmid=20110992|bibcode=2010Natur.463..485F }}</ref><ref>{{Cite journal|last1=Li|first1=Shanwei|last2=Sun|first2=Tiantian|last3=Ren|first3=Haiyun|date=27 April 2015|title=The functions of the cytoskeleton and associated proteins during mitosis and cytokinesis in plant cells|journal=Frontiers in Plant Science|volume=6|pages=282|doi=10.3389/fpls.2015.00282|issn=1664-462X|pmc=4410512|pmid=25964792|doi-access=free}}</ref><ref>{{Cite journal|last1=Hohmann|first1=Tim|last2=Dehghani|first2=Faramarz|date=18 April 2019|title=The Cytoskeleton—A Complex Interacting Meshwork|journal=Cells|volume=8|issue=4|pages=362|doi=10.3390/cells8040362|issn=2073-4409|pmc=6523135|pmid=31003495|doi-access=free}}</ref>