Q. Restriction endonucleases are
A) Present in mammalian cells for degradation of DNA when the cell dies
B) Used in genetic engineering for ligating two DNA molecules
C) Used for in vitro DNA synthesis
D) Synthesized by bacteria as part of their defence mechanism
Explanation
Restriction enzymes are degradative enzymes, which recognize and cut up DNA that is foreign to a cell. These enzymes protect bacteria against intruding DNA from other organisms such as virus or other bacterial cells.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.