Editing Genetics (section)

=== Reproduction ===
{{Main|Asexual reproduction|Sexual reproduction}}

[[File:Zellsubstanz-Kern-Kerntheilung.jpg|thumb|left|[[Walther Flemming]]'s 1882 diagram of eukaryotic cell division. Chromosomes are copied, condensed, and organized. Then, as the cell divides, chromosome copies separate into the daughter cells.]]

When cells divide, their full genome is copied and each [[Cell division|daughter cell]] inherits one copy. This process, called [[mitosis]], is the simplest form of reproduction and is the basis for asexual reproduction. Asexual reproduction can also occur in multicellular organisms, producing offspring that inherit their genome from a single parent. Offspring that are genetically identical to their parents are called [[Cloning|clones]].<ref>{{cite web |url=https://www.merriam-webster.com/dictionary/clone |title= clone|author=<!--Not stated--> |date= |website=Merriam-Webster Dictionary |publisher= |access-date=13 November 2023 |quote=}}</ref>

[[Eukaryote|Eukaryotic]] organisms often use sexual reproduction to generate offspring that contain a mixture of genetic material inherited from two different parents. The process of sexual reproduction alternates between forms that contain single copies of the genome ([[haploid]]) and double copies ([[diploid]]).<ref name=griffiths2000sect484 /> Haploid cells fuse and combine genetic material to create a diploid cell with paired chromosomes. Diploid organisms form haploids by dividing, without replicating their DNA, to create daughter cells that randomly inherit one of each pair of chromosomes. Most animals and many plants are diploid for most of their lifespan, with the haploid form reduced to single cell [[gamete]]s such as [[sperm]] or [[Ovum|eggs]].<ref>{{Cite web |title=Haploid |url=https://www.genome.gov/genetics-glossary/haploid |access-date=2024-02-10 |website=www.genome.gov |language=en}}</ref>

Although they do not use the haploid/diploid method of sexual reproduction, [[bacteria]] have many methods of acquiring new genetic information. Some bacteria can undergo [[Bacterial conjugation|conjugation]], transferring a small circular piece of DNA to another bacterium.<ref name="griffiths2000sect1304">{{cite book | veditors = Griffiths AJ, Miller JH, Suzuki DT, Lewontin RC, Gelbart|title=An Introduction to Genetic Analysis |year=2000 |isbn=978-0-7167-3520-5 |edition=7th |publisher=W.H. Freeman |location=New York |chapter-url=https://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=iga.section.1304 |chapter=Bacterial conjugation}}</ref> Bacteria can also take up raw DNA fragments found in the environment and integrate them into their genomes, a phenomenon known as [[Transformation (genetics)|transformation]].<ref name="griffiths2000sect1343">{{cite book | veditors = Griffiths AJ, Miller JH, Suzuki DT, Lewontin RC, Gelbart|title=An Introduction to Genetic Analysis |year=2000 |isbn=978-0-7167-3520-5 |edition=7th |publisher=W.H. Freeman |location=New York |chapter-url=https://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=iga.section.1343 |chapter=Bacterial transformation}}</ref> These processes result in [[horizontal gene transfer]], transmitting fragments of genetic information between organisms that would be otherwise unrelated. [[Transformation (genetics)|Natural bacterial transformation]] occurs in many [[bacteria]]l species, and can be regarded as a [[sexual reproduction|sexual process]] for transferring DNA from one cell to another cell (usually of the same species).<ref name=Bernstein2018>{{cite journal | vauthors = Bernstein H, Bernstein C, Michod RE | title = Sex in microbial pathogens | journal = Infection, Genetics and Evolution | volume = 57 | pages = 8–25 | date = January 2018 | pmid = 29111273 | doi = 10.1016/j.meegid.2017.10.024 | doi-access = free | bibcode = 2018InfGE..57....8B }}</ref> Transformation requires the action of numerous bacterial [[gene product]]s, and its primary adaptive function appears to be [[DNA repair|repair]] of [[DNA damage (naturally occurring)|DNA damages]] in the recipient cell.<ref name=Bernstein2018 />