DNA replication occurs before mitosis and cell division to ensure that each daughter cell receives a complete and accurate copy of the genome. This process happens during the S phase of the cell cycle, where the entire DNA is duplicated to maintain genetic continuity. Without DNA replication before cell division, daughter cells would end up with only half the genetic material, leading to improper function or cell death. The replication ensures genome integrity and faithful transmission of genetic information to daughter cells, which is critical for growth, development, and tissue maintenance.
