Question

The cutting of DNA at specific locations became possible with the discovery of:

• A. Probes
• B. Restriction enzymes
• C. Selectable markers
• D. Ligases

Answer 1

The correct option is B

Restriction enzymes

The correct option is B.

Explanation of the correct option:

Restriction enzymes:

1. The restriction enzyme is an enzyme that cuts the double-stranded or single-stranded DNA at a very specific nucleotide sequence that are known as the restriction sites.
2. These are very popularly known as molecular scissors.
3. The first isolated restriction enzyme was Hind II.
4. These enzymes are popularly used in various DNA cloning experiments.

Explanation of the incorrect options:

Option A:

Probes:

Probes are very commonly used to detect some specific target DNA or RNA sequences from a mixture of DNA or RNA samples.

Option C:

Selectable markers:

1. A selectable marker is necessary for maintaining the plasmid in the cell.
2. It is because of the presence of this marker that the plasmid becomes useful.

Option D:

Ligases:

It is an enzyme that works opposite of the restriction enzyme, which means it joins the two DNA sequences with the help of the formation of bonds.

Final answer: The cutting of DNA at specific locations became possible with the discovery of restriction enzymes.