Overview of Cell Cycle

Actively dividing eukaryote cells pass through a cell cycle consisting of the following phases:

  • G1 phase: Organelles except for chromosome are duplicated.
  • S phase: Chromosomes, which contains DNA are duplicated.
  • G2 phase: The cell continues to grow and prepares for mitosis.

The S phase is tightly regulated and widely conserved because accurate duplication of the DNA is critical to successful cell division.

How is DNA replicated and regulated in the S phase of the cell cycle?