Question

What is true of plasmid?

• A. Found in viruses
• B. Contains genes for vital activities
• C. Part of nuclear chromosome
• D. Widely used in gene transfer

Answer 1

The correct option is D

Widely used in gene transfer

The correct option is D.

Explanation of correct option:

1. Plasmids are extrachromosomal structures that have the ability to replicate on their own and are widely used as vectors in genetic engineering for gene transfer.
2. For example- they can carry antibiotic-resistant genes and can spread them in the animal/plant body.
3. They are genetically modified and used in recombinant DNA technology.
4. The transformation procedure can be used to insert this plasmid into a bacteria.
5. Bacteria may thus be employed as factories to replicate vast amounts of DNA fragments since they reproduce quickly.

Explanation of the incorrect option:

Option A:

Plasmids are exclusively found in bacteria and not in viruses since they do not have any role in viral replication.

Option B:

Plasmids do not contain genes for activities that are the basic needs for survival for the cells; the bacterial chromosome contains all the genes required for the vital activities of the cells.

Option C:

Plasmids are extrachromosomal circular DNA molecules that are capable of replicating on their own; they are not a part of the nuclear chromosome.

Final answer: Plasmid is widely used in gene transfer.