Question

Read the following statements about restriction enzymes and choose the option which has only correct ones.

• A. Restriction enzymes belongs to a large class of enzymes called nuclease.
• B. Restriction enzymes are of two kinds exonuclease and endonuclease.
• C. Restriction enzymes are so called because these only identify particular nucleotide sequence.
• D. In nature approximately $900$ restriction enzymes are present.

Answer 1

The correct option is C Restriction enzymes are so called because these only identify particular nucleotide sequence.

A restriction enzyme or restriction endonuclease is an enzyme that cleaves DNA into fragments at or near specific recognition sites within the molecule known as restriction sites. Restrictions enzymes are one class of the broader endonuclease group of enzymes. Restriction enzymes are so-called because they cannot cleave DNA at all sites but they are restricted to particular nucleotide sequences called restriction sites.

So, the correct answer is 'Restriction enzymes are so-called because these only identify particular nucleotide sequence'.