You will learn
- Define stomata.
- Describe gas exchange in leaves.
- Explain respiration in plants.
- Compare day and night.
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
- Stomata let gases enter and leave.
- Plants take in carbon dioxide for photosynthesis.
- Plants release oxygen.
- All living things respire.
Words to know
tiny pores on leaves
a cell that opens and closes a stoma
releasing energy from food
a gas plants take in
1. Discover: The tiny doors
Under a microscope, Naana sees tiny mouth-like gaps on the underside of a leaf. “They are stomata,” says her teacher. “Guard cells open them to let gases in and out, and close them to save water.”
Think: Why close them?
2. Understand: Gas exchange
Idea 1: Stomata
Stomata are tiny pores, mostly under leaves. Guard cells open and close them. Carbon dioxide goes in; oxygen and water vapour go out.
Idea 2: Two processes
In light, plants photosynthesise, using carbon dioxide and releasing oxygen. At all times, plants respire, using oxygen to release energy from food.
Idea 3: Day and night
In bright light photosynthesis is faster than respiration so there is a net release of oxygen. At night only respiration continues.
3. Worked examples
Example 1 (I show you): Name
Pores.
- Stomata.
- Underside.
- Tiny.
Answer: Stomata.
Example 2 (We do it together): Explain
Day.
- Photosynthesis.
- Oxygen out.
- Faster.
Answer: Net oxygen release.
Example 3 (You try): Explain
Night.
Show the steps and answer
- Respiration only.
- Oxygen in.
- CO2 out.
Answer: Only respiration.
Did you know?
A single leaf can have more than 100,000 stomata on each square centimetre.
Why this matters
Gas exchange links plants and animals through oxygen and carbon dioxide.
4. Explore: Leaf print
Paint a thin layer of clear nail varnish on a leaf (adult), peel off the print and look at stomata with a lens or microscope.
- Choose a leaf.
- Adult paints varnish.
- Peel when dry.
- Observe the print.
Think about it: what did you notice?
What did you notice? Tiny gaps appeared mostly on the underside.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- ___ are tiny pores on leaves.
- A ___ cell opens a stoma.
- ___ releases energy from food.
- Plants take in ___ dioxide.
Guided practice
Question 1. What are stomata?
Pores.
Question 2. What opens them?
Guard cells.
Question 3. What goes in?
Carbon dioxide.
Independent practice
Level 1: Start
- What are stomata?
- What opens them?
- What goes in?
- What goes out?
- What is respiration?
Level 2: Grow
- Why close?
- Why night respiration?
- Why underside?
Level 3: Stretch
- Make the print.
- Compare day and night.
- Explain.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Explain what happens at stomata in sunlight.
Show a sample answer
Use gases.
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: They do.
Fix: Mostly leaves.
8. Lesson summary and revision card
- I can define stomata.
- I can describe gas exchange in leaves.
- I can explain respiration in plants.
- I can compare day and night.
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
- Stomata let gases enter and leave.
- Plants take in carbon dioxide for photosynthesis.
- Plants release oxygen.
- All living things respire.
11. Next lesson
Next lesson: Plant food production. 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 stomata and guard cell. [2 marks]
- Explain day gas exchange. [3 marks]
- Explain night. [3 marks]
- Safety rule. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 1 each
- CO2 in [1]; oxygen out [1]; photosynthesis [1]
- Respiration [1]; oxygen in [1]; CO2 out [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 are stomata?
- What opens them?
- What goes in?
- What goes out?
- What is respiration?
- Why close?
- Why night respiration?
- Why underside?
- Make the print.
- Compare day and night.
Homework
Look at leaf undersides with a lens.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What are stomata? | Pores. | 1 |
| 2. What opens them? | Guard cells. | 1 |
| 3. What goes in? | Carbon dioxide. | 1 |
| 4. What goes out? | Oxygen. | 1 |
| 5. What is respiration? | Release energy. | 1 |
| 6. Why close? | Save water. | 1 |
| 7. Why night respiration? | Still living. | 1 |
| 8. Why underside? | Less water loss. | 1 |
| 9. Make the print. | Photo. | 1 |
| 10. Compare day and night. | Table. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Pores.; 2 Guard cells.; 3 Carbon dioxide.; 4 Oxygen.; 5 Release energy.. Level 2: 1 Save water.; 2 Still living.; 3 Less water loss.. Level 3: 1 Photo.; 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 Define stomata | 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 Describe gas exchange in leaves | 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 Explain respiration in plants | 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 Compare day and night | 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: “Plants do not respire.” They do.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Explain gas exchange.
- 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 gas exchange in leaves. You do not need to be an expert to help.
- Inspect a leaf together.
- Ask “Where are the pores?”
- Adults handle varnish.
- 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: define stomata; describe gas exchange in leaves; explain respiration in plants; compare day and night.
Prerequisite knowledge. Grade 4 ideas: parts of a plant, what plants need, life cycles and simple food chains.
Materials. Leaf, lens, tape. 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. Collect leaves.
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). Show a leaf and ask, “Where do gases go in?”
Explanation (10 min). Teach gas exchange.
Guided activity (10 min). Learners observe.
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 gas? Which process?
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. “Plants do not respire.” They do.
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 gas exchange. 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 5 Unit 3, topic 6; Next Generation Science Standards, matter and energy in organisms; Cambridge Primary Science Stage 5, biology: plants; IB Primary Years Programme, sharing the planet. These sources informed the lesson.