Curriculum fit: GCSE Biology and Combined Science (cell biology). US: middle and high school life science (structure and function).
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What Is It?
Cells are the basic units of living things. Animal and plant cells share several parts but also differ. Each part has a job, and the structure of a cell is linked to its function.
Cells are very small, so scientists use microscopes and calculate magnification to work out real sizes.
Key Formulas and Ideas
- Animal cell: nucleus, cytoplasm, cell membrane, mitochondria, ribosomes.
- Plant cell also has: cell wall (cellulose), chloroplasts and a permanent vacuole.
- Magnification = image size ÷ actual size.
- Units: 1 mm = 1000 micrometres (µm).
Worked Examples
Match Structure to Function
Which part of the cell releases energy by respiration?
- Respiration takes place in mitochondria.
- Mitochondria are found in both plant and animal cells.
✓ Answer The mitochondria
Magnification
A cell is drawn 20 mm long. Its real length is 0.1 mm. What is the magnification?
- Magnification = image size ÷ actual size.
- 20 ÷ 0.1 = 200.
✓ Answer ×200
Plant Versus Animal
Give two differences between a plant cell and an animal cell.
- A plant cell has a cell wall, an animal cell does not.
- A plant cell has chloroplasts for photosynthesis.
✓ Answer Cell wall and chloroplasts (and a permanent vacuole) are found in plant cells only
Common Mistakes to Avoid
- Saying that the cell wall controls what enters the cell. That is the cell membrane.
- Writing that animal cells have no mitochondria.
- Forgetting to convert units before calculating magnification.
- Mixing up the nucleus (controls the cell, holds DNA) with the cytoplasm.
Practice Questions
Frequently Asked Questions
Do plant cells have mitochondria?
Yes. Plants respire as well as photosynthesise, so their cells contain mitochondria too.
Do all plant cells have chloroplasts?
No. Root cells, for example, are underground and do not photosynthesise, so they have no chloroplasts.
Keep Going With These Guides
Photosynthesis Explained: Equation, Process and Limiting Factors
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GCSEHigh SchoolAPMitosis and the Cell Cycle: Stages Explained Step by Step
Learn what happens at each stage of mitosis, why cells divide and how to count cells after division, with worked examples and practice questions.
GCSEHigh SchoolAPSources and Review
Reviewed by StudyMorrow editorial review on 5 Nov 2026.