Question

Which one of the following is not applicable to plasmids?
A. Extrachromosomal DNA
B. Always linear in form
C. Single-stranded molecules
D. Autonomously replicating

• A. A & D
• B. B & C
• C. B, C & D
• D. B only

Answer 1

The correct option is B B & C

Plasmids are found in certain bacterial cells.

Plasmids are extrachromosomal DNA molecules as they exist outside the nucleoid region in bacterial cells.The chromosomal DNA is found in the nucleoid region.

Plasmids are usually circular in form, however linear plasmids also have been reported.

Plasmids are double-stranded DNA molecules.

Plasmids are autonomously replicating as they have an ori (origin of replication) site which initiates the replication.

Plasmids are used extensively in genetic engineering as vectors to carry the gene of interest into the host cell/organism.