a small circle of bacterial DNA that is independent of the main bacterial chromosome. Plasmids often contain genes for drug resistances and can be transmitted between bacteria of the same and different species: used in genetic engineering
Word origin
C20: from plasm + -id1
plasmid in American English
(ˈplæzmɪd)
noun
a small, DNA-containing, self-reproducing cytoplasmic element that exists outside the chromosome, as in some bacteria: because it can alter a hereditary characteristic when introduced into another bacterium, it is used in recombinant DNA technology