Science lesson plan · 7th grade (Year 8 in England) · 45 minutes
Energy transfer and pyramids
Ecosystems and food chains
CCSS NGSS.MS-LS2-3CCSS NGSS.HS-LS2-4England: KS3 Biology: Interactions and interdependenciesEngland: KS4 Combined Science: Ecosystems
Objective and success criteria
Students will: Energy transfer and pyramids.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Food webs and interdependence
Leads to: The carbon cycle; Calculate energy transfer efficiency between trophic levels
Materials: Food web cards, Arrows to build chains, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Food webs and interdependence). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Pond food web: algae are eaten by tadpoles and water fleas. Tadpoles and water fleas are eaten by small fish. Small fish are eaten by herons. If the small fish died, what would happen to the herons? (They would increase / They would decrease or move away / They would eat algae / Nothing) → They would decrease or move awayPrompt: What do herons eat in this web?
- Bees are declining. Why could this affect fruit farmers? (Bees make the rain / Fruit trees need honey to grow / Fewer flowers would be pollinated, so less fruit forms / Bees eat fruit) → Fewer flowers would be pollinated, so less fruit formsPrompt: What do bees carry between flowers?
- Food webs: which statement is NOT true? (Removing one species can affect many others in a food web. / Removing a predator always helps every other species. / Plants compete for light, water and minerals. / Predator and prey populations often rise and fall in cycles.) → Removing a predator always helps every other species.Prompt: Think about what happens when one population changes.
Hook · 5 min
- Show a food web and ask what would happen if one animal disappeared.
- Share the objective: Energy transfer and pyramids. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Producers in a field capture 20000 kJ of energy. About 10% of the energy passes to each next level. How much energy reaches the tertiary consumers, in kJ?
- Step 1: 20000 ÷ 1000 = 20
- Step 2: So the answer is: 20 kJ
- Answer: 20 kJ
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Producers in a field capture 10000 kJ of energy. About 10% of the energy passes to each next level. How much energy reaches the primary consumers, in kJ? → 1000 kJPrompt: 10% means divide by 10 at each step.
- A level of a food chain contains 8000 kJ. The next level gets 800 kJ. What is the percentage efficiency of the energy transfer? → 10 %Prompt: efficiency = energy passed on ÷ energy available × 100
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Producers in a field capture 100000 kJ of energy. About 10% of the energy passes to each next level. How much energy reaches the primary consumers, in kJ? → 10000 kJPrompt: 10% means divide by 10 at each step.
- A level of a food chain contains 2000 kJ. The next level gets 100 kJ. What is the percentage efficiency of the energy transfer? → 5 %Prompt: efficiency = energy passed on ÷ energy available × 100
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Food webs and interdependence.
- Use concrete materials: food web cards.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: The carbon cycle; Calculate energy transfer efficiency between trophic levels.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-7.
Free lesson plan from eurekami.com/lesson-plan-builder