When does DNA replication happen?

DNA replication happens during the S phase of the cell cycle, which is a critical period before cell division. The cell cycle is divided into several stages: G1 (gap 1), S (synthesis), G2 (gap 2), and M (mitosis). DNA replication specifically occurs in the S phase to ensure that each new cell receives a complete set of chromosomes. This replication process begins at multiple origins along the DNA, and the entire genome is duplicated to produce two complete copies. The accuracy of DNA replication is paramount as any errors can lead to mutations or genomic instability.