Editing Cell (biology) (section)

=== DNA repair ===

{{main|DNA repair}}

Cells of all organisms contain enzyme systems that scan their DNA for [[DNA damage (naturally occurring)|damage]] and carry out [[DNA repair|repair processes]] when it is detected. Diverse repair processes have evolved in organisms ranging from bacteria to humans. The widespread prevalence of these repair processes indicates the importance of maintaining cellular DNA in an undamaged state in order to avoid cell death or errors of replication due to damage that could lead to [[mutation]]. [[Escherichia coli|''E. coli'']] bacteria are a well-studied example of a cellular organism with diverse well-defined [[DNA repair]] processes. These include: [[nucleotide excision repair]], [[DNA mismatch repair]], [[non-homologous end joining]] of double-strand breaks, [[homologous recombination|recombinational repair]] and light-dependent repair ([[photolyase|photoreactivation]]).<ref>{{cite book |last1=Snustad |first1=D. Peter |last2=Simmons |first2=Michael J. |title=Principles of Genetics |edition=5th |at=DNA repair mechanisms, pp. 364–368}}</ref>