What is Nuclear DNA?
'''Nuclear DNA''' is the [[DNA]] inside the [[cell nucleus]] of [[eukaryotic]] [[cell]]s. This DNA is a [[double helix]], with two strands wound around each other. This double helix structure was first described by [[Francis Crick]] and [[James D. Watson]] in 1953.<ref>{{Cite journal|author=Watson JD, Crick FH |title=Molecular structure of nucleic acids: a structure for deoxyribose nucleic acid |journal=Nature |volume=171 |issue=4356 |pages=737–8 |year=1953 |pmid=13054692 |doi=10.1038/171737a0|bibcode = 1953Natur.171..737W |s2cid=4253007 }}</ref> This DNA is different from the DNA in [[bacteria]], [[mitochondria]] and [[plastids]] such as [[chloroplast]]s. Nuclear DNA is very long, and is bound up in [[chromosomes]] which, apart from the DNA, are [[protein]] structures. The second difference is that each eukaryote cell has two sets of DNA, one set from each parent: it is [[diploid]]. Mitochondrial and plastid DNA is relatively short, is in a circle, and there is only one set ([[haploid]]), not two.<ref>MiMi. [http://en.mimi.hu/biology/nuclear_genome.html]</ref> It is supposed that these [[organelles]] were once independent [[bacteria]] (see [[endosymbiosis]]). The consequence of nuclear DNA being double is highly important. The genes in mitochondria and plastids only change when a [[mutation]] happens. Nuclear DNA gets shuffled by the cell division known as [[meiosis]], part of [[sexual reproduction]]. This leads to a variety of offspring from any two parents. Another feature of nuclear DNA is that it is [[gene regulation|regulated]] by proteins and [[RNA]] systems which control the rate of [[transcription (genetics)|transcription]] into [[messenger RNA]]. In this way, most of the cell products are adjusted according to the circumstances.<ref>Alberts, Bruce ''et al'' 2002. ''Molecular biology of the cell''. 4th ed, Garland Science.</ref> == References == {{reflist}} {{biology-stub}} [[Category:DNA]]