Question

Match List I with List II:

LIST I	LIST II
A. Ligase	I. Reduce topological strain
B. Helicase	II. Adds phosphate group
C. Gyrase	III. Joins two open ends of DNA
D. Kinase	IV. Unwinds the DNA

Choose the correct answer from the options given below:

• (A) - (III), (B) - (I), (C) - (IV), (D) - (II)
• (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
• (A) - (II), (B) - (IV), (C) - (I), (D) - (III)

Hint:

Each enzyme in DNA replication has a specific function: helicase unwinds DNA, gyrase reduces strain, ligase joins ends, and kinase adds phosphate groups.

Answer 1

The Correct Option is C

• Ligase (A): An enzyme that joins open DNA ends by forming phosphodiester bonds, typically during replication or repair. Hence, (III).
• Helicase (B): Unwinds the DNA double helix, separating strands to facilitate replication or transcription. Hence, (IV).
• Gyrase (C): A topoisomerase that reduces topological strain in DNA caused by unwinding during replication. Hence, (I).
• Kinase (D): An enzyme that adds phosphate groups to molecules, often modifying proteins or other substrates. Hence, (II).