Cambios

[[File:Plasmid (numbers).png|300px|thumb|Plasmids into bacteriaPlásmidos en bacterias: 1-Bacterial DNA El ADN bacteriano 2-PlasmidsLos plásmidos]]A Un '''plasmidplásmido''' is a separate intracellular fragment of DNAes un fragmento intracelular separada de ADN<ref name=Alberts>{{cite book|author=Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; Walters, Peter|title=Molecular Biology of the Cell|edition=5th|publisher=Garland Science|year=2008|location=New York and London|page=21|isbn=0-8153-4105-9}}</ref> that can replicate independently of, chromosomal DNA within a cellque puede replicarse independientemente del ADN cromosómico dentro de una célula. plasmids are found primarily in bacteria, but may be present occasionally in [[archaea]] and [[eukaryotes]]. Plasmids are generally circular DNA molecules.<ref name=watson>{{cite book|author=Watson, Jamed D.; Baker, Tania A.; Bell, Stephen P.; Gann, Alexandrer; Levine, Michael. Losick, Richard|title=Molecular Biology of the Gene|edition=5th|publisher=Pearson, Benjamin Cummings/CSHL Press|year=2004|location=San Francisco, CA|page=111;131|isbn=0-8053-4642-2}}</ref> Unlike the chromosomal DNA of bacteria, plasmids are typically not essential for bacterial growth.<ref name=watson /> Plasmids provide an important additional dimension towards the flexibility of the body's response to changes in their environment, whether those changes are hostile or potentially favorable.<ref name=Dale>{{cite book|author=Dale, Jeremy W.; Park, Simon F|title=Molecular Genetics of Bacteria|page=137-164|year=2004|location=West Sussex, England|publisher=John Wiley & Sons|edition=4th|isbn=0-470-85084-1}}</ref>