Plasmid is a structure (loop) in bacterial cells consisting of DNA that can exist and replicate independently of the chromosome. These are extrachromosomal circular double stranded DNA (dsDNA) which provide genetic instructions for certain cell activities (e.g. resistance to antibiotic drugs). They can be transferred from cell to cell in a bacterial colony. Plasmids are widely used as vectors to produce recombinant DNA for gene cloning.