During which phase of the cell cycle does DNA replication occur?

DNA replication occurs during the S phase of the cell cycle, which stands for "synthesis." This phase is critical as it is when the entire genetic material is duplicated, allowing each daughter cell to receive an exact copy of the genome during cell division.

In this phase, enzymes like DNA polymerases synthesize new strands of DNA, ensuring that the two strands of the double helix are replicated accurately. This process is essential for cell division, as it prepares the cell to divide and ensures that genetic information is passed on correctly to the next generation of cells.

In contrast, the G1 phase involves cell growth and normal function before the DNA synthesis begins, the G2 phase is a period of further growth and preparation for mitosis without DNA replication, and the M phase refers to mitosis itself, the process of cell division. Each of these phases plays a unique role, but only the S phase is specifically dedicated to the replication of DNA.