What role does Polymerase play in DNA replication?

During DNA replication, polymerase is crucial because it adds complementary nucleotides to the growing DNA strand. Once the DNA strands are separated, polymerases synthesize new strands by matching the proper nucleotide with its complementary base on the template strand. For example, where there is an adenine (A) on the template strand, DNA polymerase would incorporate a thymine (T) in the newly forming strand. This activity is essential for accurately replicating the genetic material, ensuring that each new cell receives an exact copy of the DNA.

The other options refer to different roles or functions that other proteins or enzymes perform during the replication process. For instance, sealing fragments of DNA is the role of DNA ligase, while helicase is responsible for unzipping the DNA strands. Additionally, the initiation of replication is typically managed by proteins that recognize the origin of replication rather than polymerase itself. Therefore, the specific action of adding complementary nucleotides is what makes polymerase a pivotal enzyme in the process of DNA replication.