You will learn
- List cell functions.
- Explain respiration simply.
- Describe diffusion.
- Describe osmosis simply.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Cells take in food and oxygen.
- Respiration releases energy.
- Diffusion moves particles from crowded to less crowded.
- Osmosis is the diffusion of water.
Words to know
releasing energy from food in cells
spreading of particles from high to low concentration
movement of water through a membrane
substances a cell must remove
1. Discover: The perfume
Someone opens a perfume bottle at the back of the room. A minute later the front row smells it. “The scent particles spread out,” says Ms Danso. “That is diffusion. Cells use the same idea to take in oxygen.”
Think: Why does the smell spread without anyone fanning it?
2. Understand: Cell jobs
Idea 1: Respiration
In respiration, cells use oxygen to release energy from glucose, producing carbon dioxide and water. It happens in the mitochondria.
Idea 2: Diffusion
Diffusion is the net movement of particles from where there are many to where there are fewer. Oxygen diffuses into cells; carbon dioxide diffuses out.
Idea 3: Osmosis
Osmosis is the diffusion of water through a membrane. A plant cell in water takes in water and becomes firm; in salty water it loses water and wilts.
3. Worked examples
Example 1 (I show you): List
Functions.
- Take in.
- Respire.
- Remove waste.
Answer: Main jobs.
Example 2 (We do it together): Explain
Diffusion.
- Many to few.
- Spread out.
- No energy.
Answer: Down the gradient.
Example 3 (You try): Predict
Osmosis.
Show the steps and answer
- Water in.
- Firm.
- Salty: wilt.
Answer: Water moves.
Did you know?
Diffusion works well only over very short distances, which is why cells are small.
Why this matters
Cell functions keep every living thing alive.
4. Explore: Colour diffusion
Place a drop of food colouring in a clear cup of still water and watch it spread, comparing warm and cool water.
- Fill two cups.
- Add one drop to each.
- Watch.
- Compare.
Think about it: what did you notice?
What did you notice? Colour spread faster in warm water.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- ___ is releasing energy from food in cells.
- ___ is the spreading of particles.
- ___ is movement of water through a membrane.
- ___ is a substance a cell must remove.
Guided practice
Question 1. What is respiration?
Energy release.
Question 2. What is diffusion?
Spreading.
Question 3. What is osmosis?
Water movement.
Independent practice
Level 1: Start
- What is respiration?
- What is diffusion?
- What is osmosis?
- Where does respiration happen?
- What is waste?
Level 2: Grow
- Why small cells?
- Why oxygen?
- Why warm faster?
Level 3: Stretch
- Run the test.
- Compare.
- Explain.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Explain how oxygen gets into a cell.
Show a sample answer
Use diffusion.
Another one. Tell a family member one thing from this lesson. Use the words you learned.
Show a sample answer
A clear sentence that uses at least one word from Words to know.
7. Common mistakes
Fix: No.
Fix: Breathing is different.
8. Lesson summary and revision card
- I can list cell functions.
- I can explain respiration simply.
- I can describe diffusion.
- I can describe osmosis simply.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- Cells take in food and oxygen.
- Respiration releases energy.
- Diffusion moves particles from crowded to less crowded.
- Osmosis is the diffusion of water.
11. Next lesson
Next lesson: Unicellular organisms. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- Define diffusion and osmosis. [2 marks]
- State the word equation for respiration. [3 marks]
- Explain why cells are small. [3 marks]
- Safety rule. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 1 each
- Glucose + oxygen [1]; to carbon dioxide + water [1]; energy released [1]
- Diffusion distance [1]; fast supply [1]; waste removal [1]
- Any [1]; reason [1]
Score guide: 9 to 10 = secure. 6 to 8 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- What is respiration?
- What is diffusion?
- What is osmosis?
- Where does respiration happen?
- What is waste?
- Why small cells?
- Why oxygen?
- Why warm faster?
- Run the test.
- Compare.
Homework
Describe a smell spreading in your home.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What is respiration? | Energy release. | 1 |
| 2. What is diffusion? | Spreading. | 1 |
| 3. What is osmosis? | Water movement. | 1 |
| 4. Where does respiration happen? | Mitochondria. | 1 |
| 5. What is waste? | Unwanted. | 1 |
| 6. Why small cells? | Short distances. | 1 |
| 7. Why oxygen? | Respiration. | 1 |
| 8. Why warm faster? | Particles move more. | 1 |
| 9. Run the test. | Notes. | 1 |
| 10. Compare. | Table. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Energy release.; 2 Spreading.; 3 Water movement.; 4 Mitochondria.; 5 Unwanted.. Level 2: 1 Short distances.; 2 Respiration.; 3 Particles move more.. Level 3: 1 Notes.; 2 Table.; 3 Sentence..
Quiz answers: 1 B, 2 C, 3 A, 4 B, 5 C, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 B, Challenge 2 C.
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 List cell functions | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Explain respiration simply | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Describe diffusion | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Describe osmosis simply | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: “Diffusion needs energy.” No.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Explain cell functions.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child studies cell functions. You do not need to be an expert to help.
- Watch tea spread.
- Ask “Why does it spread?”
- Mind spills.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: list cell functions; explain respiration simply; describe diffusion; describe osmosis simply.
Prerequisite knowledge. Grade 5 ideas: living things, plant and animal parts and using a hand lens.
Materials. Cups, food colouring, water. Low-resource options: use chalk or charcoal on a board or wall, drawings in the sand, and objects from the classroom instead of printed materials.
Preparation. Warm water.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Open a scent and ask, “Who smells it first?”
Explanation (10 min). Teach cell functions.
Guided activity (10 min). Learners test.
Independent activity (10 min). Learners explain.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Which way do particles move? Why?
Teacher explanation notes. Start with real objects and safe, hands-on observation. Then talk about what was seen, then draw and write. Always say “how do you know?”. Keep to the safety notes, and use local, safe materials.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and pictures, short sentences and a partner. Let learners point, show or draw instead of writing. Extension. Ask learners to find a new example at home and explain how they know.
Formative assessment. Listen to learners read and explain, ask “how do you know?”, and check the independent work.
Misconceptions. “Diffusion needs energy.” No.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz, the 10-mark exam practice and the worksheet on this page. All answers and marking guides are in the answer sections above. Re-check every answer before use.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Explain cell functions. Enrichment. Look for one new example near your home or school, draw it and explain it to someone. Homework. See above.
Teacher reflection. After teaching, record: which ideas learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points: Next Generation Science Standards, Cambridge Primary Science and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Research used to shape this lesson. Courseversity Science curriculum, Grade 6 Unit 3, topic 6; Next Generation Science Standards, structure and function; Cambridge Lower Secondary Science, cells and organisation; IB Primary Years Programme, who we are. These sources informed the lesson.