EVERYDAY SCIENCE

Detailed explanation-1: -Plasmids are extra-chromosomal small circular DNAs that are capable of replicating independently of the host, and are present throughout a variety of different microorganisms, most notably bacteria.

Detailed explanation-2: -A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell’s chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance.

Detailed explanation-3: -Plasmid DNA Plasmids are small circular DNA molecules consisting of just a few genes to more than a hundred. Among the important genes carried in plasmids are those coding for resistance to a wide range of antibiotics and genes that allow plasmids to be transferred to other bacteria, even to other species of bacteria.

Detailed explanation-4: -Plasmids contain three components: an origin of replication, a polylinker to clone the gene of interest (called multiple cloning site where the restriction enzymes cleave), and an antibiotic resistance gene (selectable marker). Plasmids are usually isolated before they are used in recombinant techniques.

Detailed explanation-5: -Most bacteria have double-stranded circular DNA as their genetic material. This circular DNA is suspended in the cytoplasm with other proteins as a distinct structure called the nucleoid. Some may have more than one circular DNA and some bacteria like Streptomyces have linear double-stranded DNA.