You will learn
- Describe what the brain does.
- Link senses to the brain.
- Explain reflexes.
- Protect the brain.
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
- The brain controls the body.
- Nerves carry messages to and from the brain.
- The brain helps us think and remember.
- The skull protects it.
Words to know
a thread that carries messages
a quick action without thinking
the ability to remember
the bone that protects the brain
1. Discover: The hot cup
Ebo touches a warm cup and pulls his hand back before he knows why. “That was a reflex,” his teacher says. “Your nerves sent a quick message to protect you.”
Think: Why is a fast reflex helpful?
2. Understand: The brain
Idea 1: Control centre
The brain is the body’s control centre. It helps us think, learn, feel, move and remember.
Idea 2: Messages
Nerves carry messages from the eyes, ears, nose, tongue and skin to the brain, and from the brain to the muscles.
Idea 3: Reflex and protection
A reflex is a very fast action, like blinking. The skull protects the brain. We wear helmets for extra safety.
3. Worked examples
Example 1 (I show you): Control
Brain does what?
- Thinks.
- Controls.
- Remembers.
Answer: The brain controls the body.
Example 2 (We do it together): Nerves
Message path.
- Senses to brain.
- Brain to muscles.
- Nerves.
Answer: Nerves carry messages.
Example 3 (You try): Reflex
Blink.
Show the steps and answer
- Fast.
- No thinking.
- Reflex.
Answer: Blinking is a reflex.
Did you know?
The human brain has about 86 billion nerve cells.
Why this matters
A healthy brain helps us learn, play and stay safe.
4. Explore: Reaction time
Test reaction time with a ruler drop.
- Partner holds a ruler.
- You catch it as it falls.
- Read the distance.
- Compare tries.
Think about it: what did you notice?
What did you notice? Reaction time was quick but varied.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- The ___ controls the body.
- ___ carry messages.
- A ___ is a quick action.
- The ___ protects the brain.
Guided practice
Question 1. What does the brain do?
Controls the body.
Question 2. What are nerves?
Message threads.
Question 3. What is a reflex?
Quick action.
Independent practice
Level 1: Start
- What does the brain do?
- What are nerves?
- What is a reflex?
- What protects the brain?
- What do we wear for safety?
Level 2: Grow
- Why do we need reflexes?
- Why wear helmets?
- Why practise memory?
Level 3: Stretch
- Do the ruler test.
- Draw message paths.
- Explain a reflex.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Name a reflex.
Show a sample answer
Blinking.
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: It controls the whole body.
Fix: They are automatic.
8. Lesson summary and revision card
- I can describe what the brain does.
- I can link senses to the brain.
- I can explain reflexes.
- I can protect the brain.
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
- The brain controls the body.
- Nerves carry messages to and from the brain.
- The brain helps us think and remember.
- The skull protects it.
11. Next lesson
Next lesson: The heart. 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.
- State two jobs of the brain. [2 marks]
- What do nerves do? [2 marks]
- Explain a reflex. [3 marks]
- How do we protect the brain? [2 marks]
- Safety rule? [1 mark]
Total: 10 marks.
Marking guide and model answers
- Any two [1 each]
- Carry [1]; messages [1]
- Quick [1]; automatic [1]; protects [1]
- Skull [1]; helmet [1]
- Any [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 does the brain do?
- What are nerves?
- What is a reflex?
- What protects the brain?
- What do we wear for safety?
- Why do we need reflexes?
- Why wear helmets?
- Why practise memory?
- Do the ruler test.
- Draw message paths.
Homework
Test your reaction time three times with a family member and record it.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What does the brain do? | Controls the body. | 1 |
| 2. What are nerves? | Message threads. | 1 |
| 3. What is a reflex? | Quick action. | 1 |
| 4. What protects the brain? | Skull. | 1 |
| 5. What do we wear for safety? | Helmet. | 1 |
| 6. Why do we need reflexes? | Protect us. | 1 |
| 7. Why wear helmets? | Protect brain. | 1 |
| 8. Why practise memory? | Remember better. | 1 |
| 9. Do the ruler test. | Table. | 1 |
| 10. Draw message paths. | Diagram. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Controls the body.; 2 Message threads.; 3 Quick action.; 4 Skull.; 5 Helmet.. Level 2: 1 Protect us.; 2 Protect brain.; 3 Remember better.. Level 3: 1 Table.; 2 Diagram.; 3 Paragraph..
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 Describe what the brain does | 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 Link senses to the brain | 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 reflexes | 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 Protect the brain | 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: “The brain is only for thinking.” It controls the whole body.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Explain what the brain does.
- 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 learns how the brain works. You do not need to be an expert to help.
- Play a safe catching game.
- Ask, “Who sent the message?”
- Wear helmets when needed.
- 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: describe what the brain does; link senses to the brain; explain reflexes; protect the brain.
Prerequisite knowledge. Grade 2 body ideas: the five senses, parts of the body, healthy food, exercise and washing hands.
Materials. Rulers, notebooks, pencils. 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. Set up testing pairs.
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 blink and ask, “Did you decide?”
Explanation (10 min). Teach the brain.
Guided activity (10 min). Learners test reaction.
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. What does the brain do? What is a reflex?
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. “The brain is only for thinking.” It controls the whole body.
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 what the brain does. 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 3 Unit 4, topic 2; Next Generation Science Standards, structure and function in living things; Cambridge Primary Science Stage 3, plants and humans; IB Primary Years Programme, who we are and how the world works. These sources informed the lesson.