Question

Main function of restriction endonuclease enzyme is :-

• A. Useful in genetic engineering
• B. Protects the bacterial DNA against foreign DNA
• C. Helpful in transcription
• D. Helpful in protein synthesis

Answer 1

The correct option is B Protects the bacterial DNA against foreign DNA

Restriction endonuclease enzyme cleaves $\text{DNA}$ at specific sites along the molecule. In the bacterial cell, restriction enzymes cleave foreign $\text{DNA}$, thus eliminating infecting organisms. The restriction enzyme prevents replication of the bacteriophage $\text{DNA}$ by cutting it into many pieces. This is the reason they are an important tool of recombinant $\text{DNA}$ technology (genetic engineering).

So, the main function of restriction endonuclease enzyme is to protect the bacterial $\text{DNA}$ against foreign $\text{DNA}$.