Teacher sheet · Ages 10–11 · about 45–50 minutes
How an ecosystem works
Lesson page: echoesof.science/school/ecosystems/ages-10-11/ · Pupil worksheet: echoesof.science/school/ecosystems/ages-10-11/print/
Learning aims
- Describe an ecosystem in terms of biotic and abiotic factors.
- Explain the roles of producers, consumers and decomposers.
- Explain how a change in one part of an ecosystem affects other parts (Yellowstone wolves).
- Build and observe a model ecosystem over time.
Lesson plan
| Time | Activity |
|---|---|
| 5 min | Starter: what would happen to a pond if all the plants died? |
| 10 min | Read the text; sort the Yellowstone story into a chain of causes. |
| 20 min | Build the bottle ecosystems in groups. |
| 5 min | Producer, consumer or abiotic? game or quiz. |
| 5 min | Set up the observation diary; observe twice a week for 4 weeks. |
Materials for the experiment
- A large clear jar or plastic bottle with a lid
- Washed gravel
- Potting compost
- 2–3 small plants such as moss, small ferns or small leafy houseplants
- A spoon and a spray bottle of water
- Observation diary
Safety: Use a plastic bottle or have an adult handle glass jars. Wear gloves when handling compost and wash your hands afterwards. Keep the jar out of direct sun and away from heaters. Do not add animals to the jar.
Common misconceptions
| Pupils may think… | Actually… |
|---|---|
| Plants get their food from the soil. | Plants make their own food using energy from sunlight; soil gives water and minerals. |
| Abiotic factors are not part of the ecosystem. | Non-living factors like temperature, water and rocks are part of every ecosystem. |
| Removing a predator always helps the animals it eats. | It can harm the whole ecosystem; in Yellowstone, wolves helped plants, beavers and birds return. |
Worksheet answers
- Biotic: e.g. moss, fern, any small insects that came with the plants. Abiotic: e.g. gravel, compost, water, air, light, temperature.
- The plants are producers and need light to make their food; without light they cannot make food and the ecosystem would fail.
- Any correct chain, e.g. grass (producer) → grasshopper (primary consumer) → mouse (secondary consumer), with arrows showing what is eaten by what.
- Elk became scarce where wolves were, so willows, cottonwoods and aspens grew back; the willows then helped beavers and birds.
Quiz answers
- Which of these is an abiotic factor? Temperature. Abiotic means non-living.[1]
- What do producers do? Make their own food from sunlight. Plants and phytoplankton are producers.[2]
- What is the first source of energy for almost every ecosystem? The Sun. Producers capture energy from sunlight.[2]
- What happened to willows in Yellowstone after wolves returned? They grew back. Fewer elk where wolves were meant willows could recover.[4]
- Why does a sealed bottle garden rarely need watering? Water evaporates, condenses and runs back down. Moisture is re-circulated inside the jar.[5]
- What is a keystone species? A species without which the ecosystem would be very different. Keystone species help define a whole ecosystem.[1]
Going further
Make a second bottle and keep it in a dark cupboard (the fair test: only the light is different). Compare both bottles after two weeks. What does this show about producers?
Sources used in this lesson
- [1] Ecosystem (National Geographic Education): reliability Medium-high
- [2] Energy flow and the 10 percent rule (National Geographic Education): reliability Medium-high
- [4] Study documents wolves' role in transforming Yellowstone (The Wildlife Society): reliability Medium-high
- [5] Terrariums and bottle gardens (Royal Horticultural Society): reliability High
Full list with links and a note on each source's reliability: echoesof.science/school/ecosystems/sources/
Privacy: the lesson pages have no ads, no tracking and no cookies. Quiz answers and game scores stay in the pupil's browser. A short video for each age is coming.