Question

Restriction endonucleases are

• A. used for in vitro DNA synthesis
• B. used in genetic engineering
• C. synthesized by bacteria
• D. present in mammalian cells for degradation of DNA.

Answer 1

Answer: (B), (C)

The correct options are
B used in genetic engineering
C synthesized by bacteria

Restriction endonucleases (restriction enzymes) are enzymes that digest double stranded DNA following the recognition of specific nucleotide sequences. This is achieved by cleaving the two phosphodiester bonds, one within each strand of the DNA duplex. Restriction endonuclease was discovered in bacteria, which use
them as a defense mechanism against bacteriophages.