Question

Q. Which of the following correctly describes the function of a restriction enzyme and DNA ligases respectively?

• A. Cutting and degradation of sticky ends of DNA molecules
• B. Binding and holding the non-sticky ends of DNA together
• C. Creating a fork-like structure from the helical strands
• D. Cleaves DNA at specific sites and joining the DNA ends

Answer 1

The correct option is D Cleaves DNA at specific sites and joining the DNA ends

Explanation:

Restriction enzymes, also known as restriction endonucleases, are proteins produced by bacteria that cleave DNA at specific sites along the molecule. Inside the bacterial cell, they cleave foreign DNA, thus eliminating infecting organisms.

DNA ligase is an enzyme that can catalyze the joining of two large molecules by forming a new chemical bond. It catalyzes the joining of the 3′-OH to the 5′-phosphate through a two-step mechanism.