When does the replication of DNA occur?

The replication of DNA occurs during the S phase (synthesis phase) of the cell cycle. This phase takes place between the first gap phase (G1 phase) and the second gap phase (G2 phase) of the cell cycle and is crucial for passing genetic material accurately to daughter cells during cell division. During the S phase, existing DNA unwinds, separating into individual strands, serving as templates for the synthesis of new, complementary strands. Various proteins and enzymes, including DNA polymerase, play crucial roles in the precise copying of DNA during replication. Ultimately, the duplication of DNA in the S phase prepares the cell for accurate chromosomal segregation, ensuring inheritance of a complete set of genes to both daughter cells upon cell division.