Question

Which vector can clone only a small fragment of DNA?

• A. Plasmid
• B. Cosmid
• C. Bacterial Artificial chromosomes (BAC)

Answer 1

The correct option is A

Plasmid

The correct option is A.

Explanation of correct option:

1. The vector that can clone only a small fragment of DNA is plasmid which is also the standard cloning vector.
2. Plasmids are circular extra chromosomal DNA that are autonomously replicating.
3. One of the most commonly used vector is pBR322 plasmid.

Explanation of incorrect options:

Option B:

1. Cosmid is used in cloning larger DNA fragments of size ranging from 50 kb to 100 kb.

Option C:

1. BAC is used to clone much larger DNA fragments with size well over 1000 kb.

Final answer: The vector which can clone only a small fragment of DNA is Plasmid.