NEET BIOLOGY

Detailed explanation-1: -A plasmid is a small circular DNA molecule found in bacteria and some other microscopic organisms. Plasmids are physically separate from chromosomal DNA and replicate independently.

Detailed explanation-2: -Plasmid DNA is a part of extrachromosomal DNA that is separated from the genomic DNA. It typically occurs inside the prokaryotic cells and is circular in nature. When compared to chromosomes, it is a smaller molecule and may vary in its number in a particular cell.

Detailed explanation-3: -They are most commonly found as small circular, double-stranded DNA molecules in bacteria; however, plasmids are sometimes present in archaea and eukaryotic organisms. In nature, plasmids often carry genes that benefit the survival of the organism and confer selective advantage such as antibiotic resistance.

Detailed explanation-4: -Plasmids are usually circular molecules of DNA, although occasionally, plasmids that are linear or made of RNA exist. They may be found as single or multiple copies and may carry from half a dozen to several hundred genes.