What is the role of DNA polymerase in DNA replication?

DNA polymerase plays a crucial role in DNA replication by adding complementary bases to the growing DNA strand. During replication, the DNA double helix unwinds, and the two strands separate. DNA polymerase then synthesizes a new strand by matching the appropriate complementary nucleotides to the exposed bases on the template strand. This process ensures that each new DNA molecule is an accurate copy of the original.

In addition to its primary function of base addition, DNA polymerase also has proofreading abilities, allowing it to correct errors during replication. This fidelity is essential for maintaining the integrity of the genetic information being copied.

While other options mention tasks that are part of the broader replication process—such as breaking hydrogen bonds or combining fragments of DNA—these tasks are typically carried out by different enzymes and processes. For example, helicase is responsible for unwinding the DNA and breaking the hydrogen bonds, and ligase is involved in joining DNA fragments on the lagging strand. Thus, the primary and defining role of DNA polymerase is its ability to add complementary bases during the formation of new DNA strands.