What are plasmids? Describe their role in bacteria.

Explanation

A plasmid is usually a circular (sometime linear), double strandad DNA, that can replicate itself autonomously. These are found in the cytoplasm of the bacterial cell, plasmids normally remain separated from the chromosome, but sometimes may integrate into it temporarily and replicate with it incidentally.
Plasmids are the extrachromosomal circular, independently replicating unit besides nucleoid in the bacterial cell.
Plasmids are used to transfer the information from one cell to another, i.e., transfer of important ganes (e.g., they may confer resistance of particular antibiotics to their bacterial cells), enabl to metabolise a nutrient, which normally a bacteria is unable to. It also helps in conjugation of bacteria. These days, plasmids are used in a variety of recombination experiments, as cloning vectors. A such example of plasmid vector is given below in figure.