Question

Which enzyme catalyses the synthesis of a new strand for a DNA molecule by linking nucleotides to the developing strand?

• A. RNA polymerase
• B. DNA ligase
• C. Topoisomerase
• D. DNA polymerase

Answer 1

Answer: (D)

• RNA polymerase helps in DNA dependent RNA synthesis. This process is known as transcription. DNA strands are used as a template to synthesize RNA molecules.
  
• DNA ligase is used to join DNA segments during DNA repair or during replication (to join Okazaki fragments of the lagging strands).
  
• DNA polymerase works in the pair to synthesis new strand for DNA molecule from deoxyribonucleotides. In other words, it helps in DNA dependent DNA synthesis.
  
• Topoisomerase enzyme participates in overwinding or unwinding of DNA. During DNA replication or transcription, DNA becomes overwound ahead of the replication fork. It binds to DNA and cut the phosphate backbone of either one or both the DNA strands.
  

So, the correct option is 'DNA polymerase'.