Feeding relationships in an ecosystemIGCSE Biology

Feeding typesOrganisms can be grouped in several ways. One way of doing this is based on how they obtain their food.

Some organisms are producers. Producers make their own food.

Plants produce their own food using light energy from the Sun. Some types of bacteria can also make their own food by using light or chemical reactions.

Consumers cannot make their own food. They must consume other organisms to get the food that they need.

Can you sort out the following organisms into

producers and consumers?

ConsumersConsumers can be grouped into different types:

Herbivores:These consumers eat producers. Herbivores include some types of plants and bacteria.

Carnivores:These consumers eat other consumers.

Omnivores:These consumers eat other consumers and producers. Omnivores eat animals and plants. Most humans are omnivores.

Can you sort out the following into

herbivores, carnivores and omnivores?

Food chainsA food chain is a sequence which shows how each individual feeds on the organism below it in the chain. Each arrow means ‘eaten by’.

caterpillarleaf bird fox

In this food chain a leaf is eaten by a caterpillar, which is then eaten by a bird, which is then eaten by a fox.

Energy is transferred from one organism to another in the direction of the arrow, showing the flow of energy through the chain.

Producer, herbivore or carnivore?

What are the feeding types of the animals in this food chain?

From a food chain, we can tell if an organism is a producer, a herbivore or a carnivore.

If the producer is a plant, only a small part of it might be involved in the food chain, such as its seeds, fruits, leaves or even dead leaves.

Food chains always start with a producer. The source of energy for all food chains is always the sun

snailleaf bird owl

Ranking consumersConsumers eat plants or animals, or both. A food chain can be used to rank different types of consumers.

Producers – make their own food. Primary consumers – eat producers. Secondary consumers – eat primary consumers. Tertiary consumers – eat secondary consumers.

producer primaryconsumer

secondaryconsumer

tertiaryconsumer

seaweed limpet crab human

Group challengeCan you use as many of these terms you have met correctly in labelling the following food chain?

Producer

Green plant

Primary consumer Secondary

consumerTertiary consumer

HERBIVORE CARNIVORE

If it also eats seeds and nuts it would be an

TOP CARNIVORE

OMNIVORE

Arrows show energy flow

Now try your food chains!