BioMasterThe cell cycle and interphase (G1, S, G2, M)
What the cell does between divisions. The phases in order, where DNA is duplicated and why interphase is not a 'resting phase'.
Direct answer: The cell cycle has two main stages: interphase (G1 growth, S synthesis/DNA replication and G2 preparation) and the M phase (mitosis + cytokinesis). DNA is duplicated in the S phase, not during mitosis.
Phases of the cell cycle
| Phase | What happens |
|---|---|
| G1 | The cell grows and makes proteins and organelles. |
| S | DNA replicates: each chromosome ends up with 2 chromatids. |
| G2 | Final growth and preparation to divide. |
| M | Mitosis (DNA distribution) + cytokinesis (cytoplasm division). |
Checkpoints and G0
The cycle has checkpoints (G1/S, G2/M) that verify everything is correct before continuing. Some cells leave the cycle into a resting state called G0 (for example, neurons).
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Study Biology free on BioMasterFrequently asked questions
What are the phases of the cell cycle?
Interphase (G1, S, G2) and the M phase (mitosis and cytokinesis).
In which phase does DNA replicate?
In the S phase of interphase.
Is interphase a resting phase?
No. It is the longest and most active stage; the cell grows and duplicates its DNA.