Plasmid:
-a genetic structure in a cell that can replicate independently of the chromosomes
-typically a small circular DNA strand in the cytoplasm of a bacterium or protozoan
-they typically have a small number of genes and can be passed from one cell to another
-often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance.
When is it used?
-Plasmids are much used in the laboratory manipulation of genes.
-Scientists use recombinant DNA methods to splice genes that they want to study into a plasmid.
-When the plasmid copies itself, it also makes copies of the inserted gene.
Which organism uses it?
Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes.
