NEET2026ZoologyBiotechnology - Principles and ProcessesActual
Which of the following statements are not true regarding restriction endonucleases ? A. They are called molecular scissors. B. These are the enzymes responsible for restricting the growth of bacteriophages in E. coli . C. They cut the DNA only at the centre of the palindromic sites. D. They remove nucleotides only from the ends of DNA fragments. E. They recognise specific palindromic base-sequences. Choose the answer
Options
- AA and B only
- BA and E only
- CD and E only
- DC and D only
Correct answer
D. C and D only
Step-by-step solution
Restriction endonucleases are commonly known as molecular scissors as they cut DNA at specific locations. Thus, statement A is true. They were discovered for their ability to restrict the growth of bacteriophages in bacteria such as E. coli . Thus, statement B is true. Restriction endonucleases cut the DNA helix a little away from the centre of the palindromic sites, but between the same two bases on the opposite strands. Thus, statement C is incorrect. Exonucleases remove nucleotides from the ends of the DNA, wher