Simple Food Chains

Follow energy through a habitat from producers to consumers, and see what happens when a food chain changes.

About 3 min read
  • Read and draw a food chain
  • Identify producers and consumers
  • Predict the effect of a change in a food chain
Before you start

You know that living things need food for energy, and that plants make their own food using sunlight.

Who eats what?

A food chain shows how energy passes from one living thing to the next. Most food chains start with a green plant, which captures energy from the Sun. Animals then get energy by eating plants or other animals. The arrows in a food chain show the direction in which energy moves.

Definition: producer

A living thing that makes its own food, such as a green plant.

Definition: consumer

An animal that gets energy by eating other living things.

Reading a food chain

Look at this chain:

Maths
grass → rabbit → fox

Grass is the producer. The rabbit is the first consumer and the fox is the second consumer. Because the fox eats other animals, it is a predator. The rabbit is its prey.

Predict a change

In the chain grass → rabbit → fox, disease kills many rabbits. What may happen to the grass and the foxes?

Fewer rabbits eat the grass, so the amount of grass may increase.

Foxes have less food, so the number of foxes may fall.

Answer: Grass may increase and foxes may decrease.

The arrow points to the eater

Read the arrow as gives energy to. It does not mean eats.

Exam focus
Say it like this“There are fewer rabbits, so foxes have less food.”
Not like this“Foxes get sad.” — Explain the change using food and energy.
Common mistakeDrawing arrows backwards from the animal to the food it eats.

Practice

In leaf → caterpillar → bird, name the producer.
The leaf, because plants make their own food.
In the same chain, name a consumer.
The caterpillar or the bird.
What do the arrows in a food chain show?
The direction in which energy passes.
Going further
In leaf → caterpillar → bird, all the birds leave. Explain what may happen to the leaves.
Caterpillars increase because fewer are eaten. They eat more leaves, so the number of leaves may fall.

Quick check

Food chains quick check

What usually starts a food chain?

It captures sunlight and makes food, which brings energy into the chain.

In grass → zebra → lion, what is the zebra?

It gets energy by eating grass, so it cannot make its own food.

What does an arrow in a food chain point towards?

Energy passes along the arrow from the food to the organism eating it.
Key takeaways
  • Food chains show how energy moves.
  • Producers make food and consumers eat other living things.
  • Arrows show the direction of energy.
  • A change to one organism can affect the others.
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