AIIMS2003ZoologyBiotechnology - Principles and Processes
Restriction enzymes:
Options
- Aare endonucleases which cleave DNA at specific sites
- Bmake DNA complementary to an existing DNA or RNA
- Ccut or join DNA fragments
- Dare required in vectorless direct gene transfer.
Correct answer
A. are endonucleases which cleave DNA at specific sites
Step-by-step solution
Restriction enzymes are endonucleases which cleave DNA at specific sites. They are originally extracted from the bacterium E.coli. Type I restriction enzymes bind to a recognition site of a duplex DNA and cleave one strand only. Type II restriction enzymes are more valuable in gene manipulation and cleave the duplex at specific target sites at or near the binding site.