Cell cycle
ScienceDefinition
The cell cycle is the series of events a cell goes through from one division to the next. It includes interphase (G1, S, and G2 phases) where the cell grows and copies its DNA, and the mitotic phase where the cell divides.
How It Works
- During G1 phase, the cell grows and carries out normal functions.
- During S phase, the cell replicates all of its DNA.
- During G2 phase, the cell continues growing and prepares proteins needed for division.
- During mitosis, the nucleus divides and chromosomes are separated into two identical sets.
- During cytokinesis, the cytoplasm splits, producing two daughter cells.
Examples
- Skin cells complete the cell cycle roughly every 24 hours to replace dead cells
- Liver cells can re-enter the cell cycle to regenerate after injury
- Cancer occurs when the cell cycle loses its normal checkpoints and controls
Key Fact
The cell cycle has three major checkpoints: G1 (restriction point), G2, and the spindle checkpoint during mitosis.
Study This Concept
Practice cell cycle with free review games in these units: