Question

In DNA replication, the Okazaki fragments on the lagging strand are joined together by

• A. DNA polymerase
• B. DNA ligase
• C. Primase
• D. Helicase

Answer 1

Answer: (B)

• DNA ligase is an enzyme used to facilitate the joining of the DNA strands together by catalyzing the formation of the phosphodiester bond. Okazaki fragments are the short sequences of DNA nucleotides which are synthesized discontinuously and later linked together. DNA ligase plays a role in repairing these short sequences.
  
• DNA polymerase enzyme helps in DNA dependent DNA synthesis (or replication). It forms two identical DNA strands from a single DNA molecule.
  
• Primase catalyzes the synthesis of a short RNA segment called primer complementary to a ssDNA (single-stranded DNA).
  
• Helicase enzyme helps in the unwinding of the DNA structure while replication process.
  

So, the correct option is 'DNA ligase'.