Science · Unit 11

Ecosystems and Environment

How living things and their environment connect

An ecosystem is the living things in a place plus the non-living conditions they depend on, and the interesting part is how tightly the two are coupled.

The unit covers producers, consumers and decomposers, food chains and webs, how organisms are adapted to where they live, and the effect people have on all of it.

This unit breaks down into 22 short steps and 132 questions, starting at difficulty 2 and building to 4. Below you can see exactly what it covers, how the path is structured, and worked examples with explanations.

Steps: 22
Questions: 132
Difficulty: 2-4

What this unit covers

Adaptation and Survival
Protecting Nature
Producers, Consumers, Decomposers
Pollution and Human Impact
Food Chains and Webs

Where this fits

Follows Living and Non-living. Biology's Evolution and Ecology covers the same ground in more depth.

Where people slip

Energy flows through a food chain and is mostly lost at each step; nutrients cycle round and are not. That difference is why food chains are short and why decomposers matter so much.

How the unit is structured

Ecosystems and Environment runs as 22 short steps that unlock in order. 16 are practice rounds and 6 are challenge rounds that pull together everything before them. Questions start at difficulty 2 and climb to 4 as you progress.

Step 1 · easierStep 22 · harder

Challenge rounds

Example questions

30 real questions from this unit, with the answer and the reason behind it, grouped by what they practise. There are 132 in the unit altogether.

Adaptation and Survival

Choose all that applyLevel 2
1. Which of these are adaptations that help animals survive? Pick all that apply.
- A snake's fangs for injecting venomcorrect
- A cactus storing water in its stemcorrect
- A frog's long sticky tongue for catching insectscorrect
- A plastic bottle floating on water
Adaptations are features of living things that aid survival; a plastic bottle is not alive.
Fact or fibLevel 2
2. Migration means animals travel to a different area to find food or better weather.
Answer: True
Many birds and mammals migrate seasonally to reach food, warmth, or breeding grounds.
Fill the blankLevel 2
3. The white fur of an Arctic fox is an example of ____, helping it blend into the snow.
- camouflagecorrect
- migration
- hibernation
- pollination
Camouflage lets an animal blend into its surroundings to hide from predators or prey.
Match the pairsLevel 2
4. Match each living thing to an adaptation that helps it survive.
Answer: Camel = Stores fat in its hump; Polar bear = Thick fur and blubber; Cactus = Spines instead of leaves; Duck = Webbed feet
Each adaptation suits the organism to the challenges of its habitat.
Multiple choiceLevel 2
5. What is an adaptation?
- A feature that helps an organism survive where it livescorrect
- A sudden change in the weather
- A type of food chain
- A kind of pollution
An adaptation is a body feature or behavior that helps a living thing survive in its environment.
Build the sentenceLevel 3
6. Build a sentence describing natural selection.
Answer: Helpful traits help organisms survive and reproduce
Natural selection favours helpful inherited traits that improve survival and reproduction.

Food Chains and Webs

Choose all that applyLevel 2
7. Which statements about food webs are true? Pick all that apply.
- Most animals eat more than one kind of foodcorrect
- A food web shows several connected food chainscorrect
- A food web is more realistic than a single food chaincorrect
- Every food web contains only one arrow
Food webs link many chains, so animals usually have several food sources.
Fact or fibLevel 2
8. If a disease wipes out the rabbits, the foxes that eat them are not affected at all.
Answer: False
Losing a prey species reduces food for its predators, so the foxes would be affected.
Fill the blankLevel 2
9. Many food chains linked together in an ecosystem form a food ____.
- webcorrect
- pyramid
- circle
- ladder
A food web shows how the many food chains in an ecosystem overlap and connect.
Guess the numberLevel 2
10. About what percent of the energy at one level of a food chain passes to the next level?
Answer: 10 percent
Only about 10 percent of energy moves up each level; most of the rest is lost as heat.
Multiple choiceLevel 2
11. In a food chain, what does an arrow point toward?
- The organism that gets the energycorrect
- The organism that is eaten
- The sun, in every case
- The nearest decomposer
Arrows show the direction energy flows, from the food to the organism that eats it.
Match the pairsLevel 3
12. Match each trophic level to a correct example from a lake ecosystem.
Answer: Producer = Algae; Primary consumer = Water flea; Secondary consumer = Small fish; Tertiary consumer = Heron
Algae make food, water fleas eat algae, small fish eat the fleas, and herons eat the fish.

Pollution and Human Impact

Build the sentenceLevel 2
13. Build a sentence about a common cause of air pollution.
Answer: Cars release gases that pollute the air
Cars burn fuel and release gases that pollute the air we breathe.
Choose all that applyLevel 2
14. Which actions would help reduce plastic pollution in the sea? Pick all that apply.
- Using reusable bags and bottlescorrect
- Recycling plastic wastecorrect
- Joining a beach clean-upcorrect
- Throwing bottles overboard from a boat
Reducing, recycling, and cleaning up plastic all keep it out of the ocean.
Fact or fibLevel 2
15. Acid rain is caused by clean water simply evaporating from lakes.
Answer: False
Acid rain forms when gases from burning fuels mix with water in the air, not from clean evaporation.
Fill the blankLevel 2
16. Burning fossil fuels adds carbon dioxide, a ____ gas that traps heat, to the air.
- greenhousecorrect
- noble
- healthy
- breathing
Greenhouse gases like carbon dioxide trap heat and gradually warm the planet.
Guess the numberLevel 2
17. About how many years can a plastic bottle take to break down in a landfill?
Answer: 450 years
Plastics decompose very slowly, so a single plastic bottle can last for centuries.
Match the pairsLevel 2
18. Match each type of pollution to an example of it.
Answer: Air pollution = Smoke from cars; Water pollution = Oil spilled in the sea; Land pollution = Litter dumped on soil; Noise pollution = Constant loud traffic
Pollution takes different forms depending on which part of the environment it harms.

Producers, Consumers, Decomposers

Choose all that applyLevel 2
19. Which of these organisms are consumers? Pick all that apply.
- A hawkcorrect
- A deercorrect
- A spidercorrect
- A fern
Consumers get energy by eating other organisms, while a fern is a producer.
Fact or fibLevel 2
20. A caterpillar that eats only leaves is a producer.
Answer: False
The caterpillar eats plants rather than making its own food, so it is a consumer.
Fill the blankLevel 2
21. The animal that eats a plant right after the producer is called a ____ consumer.
- primarycorrect
- secondary
- top
- final
A primary consumer is the plant-eater that comes directly after the producer in a food chain.
Match the pairsLevel 2
22. Match each feeding group to how it gets food.
Answer: Producer = Makes its own food; Herbivore = Eats only plants; Carnivore = Eats only animals; Scavenger = Eats dead animals
Organisms are grouped by how they get their food.
Multiple choiceLevel 2
23. Organisms that make their own food using sunlight are called ____.
- producerscorrect
- consumers
- decomposers
- predators
Producers, like plants and algae, make their own food using energy from sunlight.
Odd one outLevel 2
24. Which of these is NOT a decomposer?
- Grasshoppercorrect
- Mushroom
- Bacteria
- Earthworm
Mushrooms, bacteria, and earthworms break down dead matter, but a grasshopper is a plant-eating consumer.

Protecting Nature

Build the sentenceLevel 2
25. Build a sentence about protecting nature.
Answer: Protecting habitats helps wild animals survive
Protecting habitats gives wild animals the space and resources they need to survive.
Choose all that applyLevel 2
26. Which actions help conserve the environment? Pick all that apply.
- Saving water at homecorrect
- Turning off lights you are not usingcorrect
- Protecting forests and wetlandscorrect
- Dumping litter into a river
Saving resources and protecting habitats are all forms of conservation.
Fill the blankLevel 2
27. When the last member of a species dies and none are left anywhere, the species is ____.
- extinctcorrect
- endangered
- protected
- native
Extinction means a species has disappeared entirely, like the dodo.
Multiple choiceLevel 2
28. What does conservation mean?
- Protecting nature and using resources wiselycorrect
- Using up resources as fast as possible
- Building factories on every open field
- Cutting down forests for firewood
Conservation means protecting living things and habitats and using resources wisely.
Fact or fibLevel 3
29. Introducing a non-native species to a new ecosystem always improves it.
Answer: False
Non-native species can become invasive, outcompeting natives and damaging the ecosystem.
Match the pairsLevel 4
30. Match each conservation term to its meaning.
Answer: Endangered = At high risk of extinction; Extinct = No members left alive; Habitat corridor = Strip linking separated habitats; Reintroduction = Returning a species to its former range
These terms describe the status of species and tools used to protect them.

Where these questions come from. Each unit starts as a plan of the concepts it should cover and the difficulty it should span. Questions are written against that plan with AI assistance, then checked by a validator that rejects anything without a single defensible answer, an explanation, or plausible wrong options. How we write questions sets out the whole process, and corrections are fixed in the bank and reach the site and the app the same day.

How you practise

This unit mixes 14 different question formats, so you are recalling and applying rather than recognising the same layout every time.

Build the sentence
Choose all that apply
Fact or fib
Fill the blank
Guess the number
Match the pairs
Multiple choice
Odd one out
Picture question
Put in order
Sort into groups
Spell it
True or false
Type the answer

Practise Ecosystems and Environment

132 questions across 22 steps. Start with step one and crawl at your own pace.

Play this unit

Read about Ecosystems and Environment

Explainers from our blog on what this unit covers. Each one ends with real questions from the bank.

What Is an Ecosystem? Living Things and Their EnvironmentLearn how organisms interact with each other and with nonliving factors such as water, soil, light, temperature, and nutrients.August 17, 2026 · 5 min read

More units in Science

See all 18 units in Science →