Question

Identify the "molecular scissors" used to cut DNA at specific sequences.

• A. DNA Ligase
• B. DNA Polymerase
• C. Restriction Enzymes
• D. RNA Polymerase

Hint:

Restriction enzymes cut DNA at specific recognition sequences, while DNA ligase joins DNA fragments together. Remember: Restriction enzyme = cut, Ligase = join.

Answer 1

The Correct Option is C

Concept: In genetic engineering, special enzymes are used to manipulate DNA. Restriction enzymes are known as molecular scissors because they cut DNA at specific recognition sequences. These enzymes were discovered in bacteria and are used by them as a defense mechanism against invading viral DNA.

Step 1: Understand the role of restriction enzymes. Restriction enzymes recognize specific short DNA sequences called recognition sites. They cut the DNA at these sites, producing fragments.

Step 2: Example of restriction enzyme action. For example, the enzyme EcoRI recognizes the sequence: \[ GAATTC \] and cuts between specific bases, producing sticky ends.

Step 3: Role in recombinant DNA technology. Restriction enzymes are widely used in:
• Gene cloning
• Recombinant DNA technology
• Genetic engineering
• DNA analysis Because they precisely cut DNA, they are called "molecular scissors".