KS3 Science · Biology · Year 7
Cells: the building blocks of life
Animal and plant cells, their parts and what each part does.
About 20 minutes
Step 1 · Wonder why it matters
Hook
37 trillion of you
Your body is made of around 37 trillion cells — far more than the number of stars in our galaxy. Each one is too small to see without a microscope, yet each one is alive.
What is inside a cell, and why are plant cells different from yours?
Step 2 · See it
Picture
See inside
Animal and plant cells share some parts. Plant cells have three extra.
| Part | Job | Animal | Plant |
|---|---|---|---|
| Nucleus | Controls the cell; contains DNA | ✓ | ✓ |
| Cytoplasm | Jelly where chemical reactions happen | ✓ | ✓ |
| Cell membrane | Controls what goes in and out | ✓ | ✓ |
| Mitochondria | Where respiration releases energy | ✓ | ✓ |
| Cell wall | Made of cellulose; supports the cell | ✗ | ✓ |
| Chloroplasts | Where photosynthesis happens | ✗ | ✓ |
| Permanent vacuole | Filled with cell sap; keeps the cell firm | ✗ | ✓ |
Step 3 · Understand how it works
Logic
Structure matches job
Plants make their own food by photosynthesis, so they need chloroplasts to capture light. Animals eat food instead, so their cells have none.
Plants do not have skeletons, so the cell wall and vacuole keep each cell rigid and the plant upright.
Cells group together to make tissues, tissues make organs, organs make organ systems, and systems make an organism.
- Cell
- Tissue
- Organ
- Organ system
- Organism
- Cell
- The smallest unit of a living thing.
- Organelle
- A part of a cell with a specific job.
- Photosynthesis
- How plants use light to make glucose from carbon dioxide and water.
- Respiration
- The reaction that releases energy from glucose, in every living cell.
Step 4 · Have a go
Do
Have a go
Draw and compare.
- 1Draw a large animal cell and a large plant cell side by side using a sharp pencil.
- 2Label every part, and add its job in a few words.
- 3Circle the three parts only found in plant cells.
- 4Challenge: root cells grow underground. Would you expect them to have chloroplasts? Explain why.
Step 5 · Remember it
Recall
Quick quiz
Match the part to its job.
0 of 4 answered
1.Which part controls the cell and contains genetic material?
2.Where does photosynthesis happen?
3.Which part is found in BOTH animal and plant cells?
4.What is the correct order?
Step 6 · Link it to your world
Reflect
Think about it
Every living thing you have ever seen is made of cells.
Why do you think a lettuce goes floppy when it has not been watered? Use the word “vacuole”.
Saved to your notebook on this device only.
Finished all six steps?
Mark it complete to collect 3 stars. That's the last lesson in this course for now.