Curriculum fit: GCSE Biology and Combined Science (cell division). US: high school life science (growth and reproduction of cells); also AP Biology.
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What Is It?
Mitosis is the type of cell division that produces two genetically identical daughter cells from one parent cell. It is used for growth, to replace damaged cells and, in some organisms, for asexual reproduction.
Mitosis is one part of the cell cycle. Before dividing, a cell spends time in interphase, when it grows and copies its DNA so each daughter cell can receive a full set.
Key Formulas and Ideas
- Cell cycle: interphase (growth and DNA replication), then mitosis, then cytokinesis (the cytoplasm splits).
- Stages of mitosis in order: prophase, metaphase, anaphase, telophase.
- After n rounds of mitosis, one cell becomes 2ⁿ cells.
- Human body cells have 46 chromosomes (diploid); mitosis keeps this number.
Worked Examples
Chromosome Number
A human skin cell with 46 chromosomes divides by mitosis. How many chromosomes does each daughter cell have?
- Before dividing, the DNA is copied during interphase.
- Mitosis shares the copies equally.
- Each daughter cell receives a full set.
✓ Answer 46 chromosomes in each daughter cell
Counting Cells
A single cell divides by mitosis 3 times. How many cells result?
- Each division doubles the number of cells.
- 2³ = 2 × 2 × 2 = 8.
✓ Answer 8 cells
Identify the Stage
Under the microscope the chromosomes are lined up along the middle of the cell. Which stage is this?
- In metaphase chromosomes align at the equator of the cell.
- Prophase has chromosomes condensing, anaphase has them pulled apart.
✓ Answer Metaphase
Common Mistakes to Avoid
- Saying mitosis makes gametes. That is meiosis.
- Forgetting that DNA is copied in interphase before mitosis begins.
- Thinking daughter cells are different from the parent cell. In mitosis they are genetically identical.
- Mixing up the order of the stages.
Practice Questions
Frequently Asked Questions
Why is mitosis important?
It lets organisms grow, repair damaged tissue and, for some species, reproduce asexually.
What can go wrong in the cell cycle?
If cell division is uncontrolled, cells divide too fast, which can form a tumour. Cancer is uncontrolled cell division.
Keep Going With These Guides
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Reviewed by StudyMorrow editorial review on 5 Nov 2026.