Plasmid: A plasmid is extranuclear circular double stranded DNA present inside the bacterial cell (eg E.coli).
Uses of Plasmid:
1) Plasmid is used in recombinant DNA technology.
2) It is used in manipulation of useful genes.
3) It is used to transfer useful genes into an organism.
4) It is used as vectors.
5) It is mainly used in commercial production of insulin.
6) It can be easily used in so many application of genetic engineering.
7) It is the main tool of genetic engineering.