Plasmids

Question

Plasmids
A) are circular DNA molecules present in many bacteria.
B) are a large linear DNA molecule isolated from bacteria.
C) are bacterial cells containing recombinant DNA molecules.
D) are transgenic animals.
E) cannot be cut with restriction enzymes.

Accepted Answer

Plasmids are small, circular DNA molecules that are found in many bacterial species. They can replicate independently of the bacterium's chromosomal DNA and often carry additional genes that provide the bacterium with beneficial traits such as antibiotic resistance or the ability to degrade certain substances.

B, C, and D are incorrect because plasmids are not large linear DNA molecules, whole bacterial cells containing recombinant DNA, or transgenic animals.

E is incorrect because plasmids can be cut with restriction enzymes. In fact, many molecular biology techniques involve cutting plasmids with specific restriction enzymes in order to insert new DNA sequences into the plasmid.