Question

When the DNA replication starts, the

• A. Leading strand produces Okazaki fragment
• B. Hydrogen bonds between the nucleotides of two strand break
• C. Phosphodiester bond between the adjacent nucleotide break
• D. Bonds between the nitrogen base and deoxyribose sugar break

Answer 1

The correct option is B Hydrogen bonds between the nucleotides of two strand break

During DNA replication breaking of H-bond is required to uncoil the DNA. When the DNA replication starts, the parent DNA double helix uncoils and splits into single DNA strands by breakdown of hydrogen bonds.
The RNA primer synthesised by primase, initiates the synthesis of the daughter strands. Followed by which DNA polymerase adds the dntps, this results in the formation of lagging and leading strands.
The lagging strand has discontinuous synthesis and results in the formation of Okazaki fragments. Synthesis on leading strand is continuous.
During DNA replication phosphodiester bond between the adjacent nucleotides and bonds between the nitrogen base and deoxyribose sugar is not broken.