You will learn
- Define food web.
- Draw a web.
- Trace several paths.
- Predict changes.
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
- Food webs link many chains.
- Animals often eat more than one food.
- Keystone species hold webs together.
- Changes spread through the web.
Words to know
many food chains joined together
a species with a big effect on its ecosystem
all of one species in a place
keeping numbers steady
1. Discover: The lake web
In Lake Volta, algae feed tilapia and insects; insects feed frogs; frogs and tilapia feed herons and humans. Aba draws arrows between all of them. “It is a web, not a line,” she says.
Think: What if the tilapia vanished?
2. Understand: Food webs
Idea 1: Many chains
A food web joins many food chains. A heron may eat fish, frogs and insects, so it appears in several chains.
Idea 2: Keystone
A keystone species such as sea otters or elephants affects many others. Removing one may change the whole web.
Idea 3: Balance
Healthy webs keep populations steady. Too many predators or too few prey cause crashes.
3. Worked examples
Example 1 (I show you): Trace
Heron.
- Fish.
- Frog.
- Insect.
Answer: Several paths.
Example 2 (We do it together): Predict
No frogs.
- Insects rise.
- Herons switch.
- Changes.
Answer: Others shift.
Example 3 (You try): Name
Keystone.
Show the steps and answer
- Big effect.
- Otters.
- Elephants.
Answer: A species with large impact.
Did you know?
Sea otters protect kelp forests by eating sea urchins that would otherwise destroy the kelp.
Why this matters
Food webs show why protecting one species protects many.
4. Explore: Web of string
Stand in a circle as organisms and connect with string to show who eats whom, then remove one and see who feels the tug.
- Choose roles.
- Pass string.
- Remove one learner.
- Notice tugs.
Think about it: what did you notice?
What did you notice? Many learners felt the tug when one left.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- A ___ web joins many food chains.
- A ___ species has a big effect.
- A ___ is all of one species in a place.
- ___ means numbers stay steady.
Guided practice
Question 1. What is a food web?
Joined chains.
Question 2. What is a keystone species?
Big effect.
Question 3. What is a population?
One species.
Independent practice
Level 1: Start
- What is a food web?
- What is a keystone species?
- What is a population?
- Name a keystone.
- Why a web?
Level 2: Grow
- Why many paths?
- Why balance?
- Why keystone?
Level 3: Stretch
- Play the game.
- Draw a web.
- Predict.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Explain what happens if a keystone species disappears.
Show a sample answer
Use a web.
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: Often several.
Fix: Spreads.
8. Lesson summary and revision card
- I can define food web.
- I can draw a web.
- I can trace several paths.
- I can predict changes.
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
- Food webs link many chains.
- Animals often eat more than one food.
- Keystone species hold webs together.
- Changes spread through the web.
11. Next lesson
Next lesson: Energy flow. 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 food web and keystone species. [2 marks]
- Draw a web with five organisms. [4 marks]
- Predict an effect. [2 marks]
- Safety rule. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 1 each
- Organisms [1]; arrows [1]; producer [1]; consumers [1]
- Species removed [1]; effect [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 a food web?
- What is a keystone species?
- What is a population?
- Name a keystone.
- Why a web?
- Why many paths?
- Why balance?
- Why keystone?
- Play the game.
- Draw a web.
Homework
Draw a food web for your area.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What is a food web? | Joined chains. | 1 |
| 2. What is a keystone species? | Big effect. | 1 |
| 3. What is a population? | One species. | 1 |
| 4. Name a keystone. | Otter. | 1 |
| 5. Why a web? | Many foods. | 1 |
| 6. Why many paths? | Choice. | 1 |
| 7. Why balance? | Stable. | 1 |
| 8. Why keystone? | Holds web. | 1 |
| 9. Play the game. | Notes. | 1 |
| 10. Draw a web. | Diagram. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Joined chains.; 2 Big effect.; 3 One species.; 4 Otter.; 5 Many foods.. Level 2: 1 Choice.; 2 Stable.; 3 Holds web.. Level 3: 1 Notes.; 2 Diagram.; 3 Table..
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 food web | 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 Draw a web | 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 Trace several paths | 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 Predict changes | 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: “Each animal eats one food.” Often several.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Build food webs.
- 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 builds food webs. You do not need to be an expert to help.
- Draw a garden web.
- Ask “What if one vanished?”
- Gentle play.
- 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 food web; draw a web; trace several paths; predict changes.
Prerequisite knowledge. Grade 4 ideas: habitats, simple food chains, producers and consumers, and adaptations of living things.
Materials. String, role cards. 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. Print cards.
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). Ask, “Who else eats a frog?”
Explanation (10 min). Teach food webs.
Guided activity (10 min). Learners play.
Independent activity (10 min). Learners draw.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Which links? What if one goes?
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. “Each animal eats one food.” Often several.
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. Build food webs. 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 8, topic 6; Next Generation Science Standards, ecosystems: interactions, energy and dynamics; Cambridge Primary Science Stage 5, biology: living things in their environment; IB Primary Years Programme, sharing the planet. These sources informed the lesson.