What is the primary function of topoisomerase during DNA synthesis?

Topoisomerase plays a critical role in DNA synthesis by managing the topology of DNA strands during replication. Its primary function involves the unwinding and winding of DNA. As the DNA double helix unwinds to allow for replication, it creates tension and supercoiling ahead of the replication fork. Topoisomerase alleviates this stress by creating temporary breaks in the DNA strands, allowing them to rotate and relieve the tension, and then rejoining the strands. This process ensures that the DNA strands remain accessible for the replication machinery and that the replication proceeds smoothly without the risk of damaging the DNA structure.

The other options describe important processes in DNA synthesis, but they do not represent the unique function of topoisomerase. Linking nucleotides together is primarily the role of DNA polymerase, while replicating DNA polymer strands is also a function of DNA polymerase. Correcting mismatched bases is the responsibility of DNA repair mechanisms, such as proofreading performed by DNA polymerases or other repair enzymes. Hence, the unique action of unwinding and winding by topoisomerase is essential for resolving supercoiling and maintaining the integrity of the DNA structure during replication.