Topics · Primary Science · Interactions: Environment
Living things and their environment
Living things depend on each other and on where they live. Food chains show which way the energy travels, and nearly every question is about what happens to everything else when one link changes.
- 113 exam papers analysed
- appears in 74% of P6 Science papers
- ~3 min read
01 What an arrow means
In a food chain the arrow means is eaten by. It follows the energy, which moves from the eaten to the eater.
So `grass → grasshopper` means the grass is eaten by the grasshopper. Drawing it the other way round is the commonest error on the topic, and it reverses the whole chain.
Every chain starts with a producer — a plant, which makes its own food. Everything after it is a consumer.
02 Producers, consumers, decomposers
Three roles, and papers ask which one an organism plays.
- Producer — makes its own food by photosynthesis. Always a plant, always first in the chain.
- Consumer — eats other living things. A herbivore eats plants, a carnivore eats animals, an omnivore eats both.
- Predator and prey — the predator hunts, the prey is hunted. An animal can be both at once: the frog above eats and is eaten.
- Decomposer — fungi and bacteria, breaking down dead matter and returning nutrients to the soil.
03 Change one link
The standard question removes an organism and asks what happens to the others. Work outwards in both directions.
Remove the frogs from the web below: grasshoppers increase, because nothing eats them; snakes decrease, because they have lost a food source; grass decreases, because more grasshoppers eat it.
Follow the chain both ways. Fewer of a predator means more of its prey; fewer of a prey means less food for its predator.
Say which direction and why. “It would be affected” scores nothing; “grasshoppers increase because their predator is gone” scores.
04 Adaptation, and people
Living things have features that suit where they live — thick fur in the cold, deep roots where it is dry, a shape that hides them from predators. That is adaptation.
Move an organism somewhere it is not adapted to and it does badly, which is what a question about a changed habitat is testing.
Human effects run both ways. Harmful: cutting down forests, polluting water and air, dropping litter — each removes habitat or food. Helpful: replanting, protecting habitats, recycling, reducing waste.
A question on deforestation wants the chain: less habitat and food, so fewer animals, plus less photosynthesis, so less oxygen and less water returned to the air.
05 How to say them
These are words most children have never said out loud, and a word you cannot say is a word you avoid using. Capitals mark the syllable you lean on. Tap the speaker to hear it.
- producersaypruh-DYOO-suhmore than oneproducers
A living thing that makes its own food. Always a plant, always first in a food chain.
- consumersaykuhn-SYOO-muhmore than oneconsumers
A living thing that eats others.
- herbivoresayHUR-bi-vormore than oneherbivores
An animal that eats only plants.
- carnivoresayKAR-ni-vormore than onecarnivores
An animal that eats only other animals.
- predatorsayPRED-uh-tuhmore than onepredators
An animal that hunts others. Its prey is what it hunts.
- food webmore than onefood webs
Several food chains joined, sharing organisms.
- habitatsayHAB-i-tatmore than onehabitats
The place a living thing lives.
- adaptationsayad-uhp-TAY-shuhnmore than oneadaptations
A feature that suits a living thing to where it lives.
06 What each level is tested on
The same topic, asked differently as it goes up. The percentage is the share of papers at that level in which it appears.
- P6
Food chains and webs, producers and consumers, the effect of removing an organism, adaptation, and human impact on the environment.
Practise P6 Interactions: Environment — 10 questions →74% of P6 papers
07 Mistakes worth knowing about
Each of these is wrong. Decide why before you open it.
“The arrow means ‘eats’.”
It means “is eaten by”, and follows the energy from the eaten to the eater. Reading it the other way reverses the whole chain.
“Remove the frogs and the grasshoppers would be affected.”
Say which way and why: they increase, because their predator is gone.
“A food chain can start with an animal.”
It starts with a producer — a plant that makes its own food.
“An animal is either a predator or prey.”
It can be both. The frog eats grasshoppers and is eaten by snakes.
“Cutting down a forest only affects the trees.”
It removes habitat and food for many animals, and reduces photosynthesis, so less oxygen is produced and less water returns to the air.
Now try it
10 questions across 1 levels, marked as you go with the working shown.