R plasmid

plasmid /plas·mid/ (plaz´mid) an extrachromosomal self-replicating structure of bacterial cells that carries genes for a variety of functions not essential for cell growth and that can be transferred to other cells by conjugation or transduction. See also episome.

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F plasmid  a conjugative plasmid found in F+ (male) bacterial cells that leads with high frequency to its transfer, and much less often to transfer of the bacterial chromosome, to an F− (female) cell lacking such a plasmid.

R plasmid , resistance plasmid a conjugative factor in bacterial cells that promotes resistance to agents such as antibiotics, metal ions, ultraviolet radiation, and bacteriophages.

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R plasmid

n.

See resistance plasmid.