Question

In recombinant DNA technology, which enzyme is used to cut DNA at specific recognition sites to produce restriction fragments?

• A. DNA polymerase
• B. Restriction endonuclease
• C. Ligase
• D. Reverse transcriptase

Hint:

In recombinant DNA technology, remember that restriction endonucleases cut DNA at specific sites, ligase joins DNA fragments, and DNA polymerase amplifies DNA. Each enzyme has a distinct role in genetic engineering.

Answer 1

The Correct Option is B

In recombinant DNA technology, restriction endonucleases (also called restriction enzymes) are used to cut DNA at specific recognition sites, producing restriction fragments with either sticky or blunt ends. These enzymes recognize palindromic sequences in the DNA and cleave the phosphodiester bonds, allowing the insertion of foreign DNA into vectors like plasmids for cloning or genetic engineering.
The roles of the other enzymes are:
- DNA polymerase: Synthesizes new DNA strands during replication or in techniques like PCR, but it does not cut DNA.
- Ligase: Joins DNA fragments by forming phosphodiester bonds, used to seal the nicks in recombinant DNA molecules.
- Reverse transcriptase: Synthesizes DNA from an RNA template, used in creating cDNA libraries, not for cutting DNA.
Thus, the enzyme used to cut DNA at specific recognition sites in recombinant DNA technology is restriction endonuclease.