Cell cycle
Definition
The cell cycle is the entire timeline starting with a single, newly created eukaryotic cell and till it has finished dividing into two daughter cells. The term "cycle" refers to the idea that upon the completion of the cell cycle for a cell, the cell cycle begins for both of its daughter cells.
States and phases of the cell cycle
The cell cycle is divided into three states; the middle state is further divided into three phases. The list of states and phases is as below:
| State | Phase | Abbreviation | What happens | Approximate duration in the case of the 24-hour cell cycle for human cells |
|---|---|---|---|---|
| Resting | Gap 0 | G0 | The cell, that has just been created, is resting. | (could vary in length, from a few hours to several days, depending on how quickly the cell needs to grow) |
| Interphase | Gap 1 | G1 | Cell growth. The G1 checkpoint ensures that everything is ready for DNA synthesis. | 11 |
| Interphase | Synthesis | S | DNA replication | 8 |
| Interphase | Gap 2 | G2 | Growth and preparation for mitosis. The G2 checkpoint ensures that everything is ready to enter the M (mitosis) phase and divide. | 4 |
| Cell division | Mitosis | M | Cell division occurs. The Metaphase Checkpoint ensures that the cell is ready to complete cell division. | 1 |
Terminal cells
For cells that do not have plans to further replicate, they are in a long-term G0 phase.