Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Molecular Basis of Inheritance

Question:

Which among the following is not correct with reference to DNA replication ?

Options:

The DNA polymerases on their own can initiate the process of replication.

There is a definite region in E. coli DNA where the replication originates.

In eukaryotes, the replication of DNA takes place at S-phase of the cell-cycle.

The replication occur within a small opening of the DNA helix, referred to as replication fork.

Correct Answer:

The DNA polymerases on their own can initiate the process of replication.

Explanation:

The correct answer is Option (1) -The DNA polymerases on their own can initiate the process of replication.

The statement "The DNA polymerases on their own can initiate the process of replication" is inaccurate. Also the replication does not initiate randomly at any place in DNA. DNA polymerases do not initiate the process of replication. Instead, they play a crucial role in elongating the new DNA strand during replication once it has been initiated by other proteins.

The initiation of DNA replication involves specific proteins that recognize the origin of replication and start the process by unwinding the DNA double helix, creating a replication bubble and a replication fork. Enzymes like helicases and initiator proteins are responsible for initiating the replication process by breaking the hydrogen bonds between base pairs and unwinding the DNA strands.

Options 2, 3, and 4 are generally accurate:

  • Option 2: There is a definite region in E. coli DNA where the replication originates, known as the origin of replication or oriC.
  • Option 3: In eukaryotes, DNA replication primarily occurs during the S-phase of the cell cycle when the cell is preparing for division.
  • Option 4: DNA replication occurs within a small opening of the DNA helix known as the replication fork, where the DNA strands separate, and new strands are synthesized.

Therefore, among the options provided, Option 1 is the one that is not correct regarding DNA replication.