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Year 8 Food chain and Food webs

Food webs and chains are every where.

In fact you are apart of a food web and a food chain.

Before we start going into detail about food chain and webs, there are some key terms your should know

Click here to learn what ecosystems, community, habitat and population mean

Food webs and chains show how the different organisms in an ecosystem interact with each other.

A food chain is just a small part of a food web. There can be multiple food chains in a food web.

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A food chain always starts with a producer.

A producer is an organism which makes its own food, like a plant, any photosynthetic or chemosynthetic organism.

After a producer, anything which eats something else in the food chain for energy is called a consumer.

There are 3 types of consumers

Lets break down as food chain

Phytoplankton are microscopic Organisms capable of photosynthesis.


Primary consumer

Secondary consumer

Tertiary consumer

Krill eat the plankton

Fish eat the Krill

Penguins eat the fish

The arrows in food chains show the way in which energy is moving, not what eats what. The reason we say energy, is because we also have parasite-host food chains.

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In an ecosystem, there are varying amounts of a particular type of animal and plants.

What you may see is a ‘pyramid of numbers’. This represents the number of organisms of a species in an ecosystem

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There is toxic material all around us. Some of it breaks down into non hazardous substances, while other can accumulate and build up in a food chain.

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Herbivores exclusively eat plant matter

Carnivore exclusively eat meat and other animals

Omnivores eat both plant and animals

Something you might not always see in a food chain/web, but are always present in every ecosystem are decomposers.

These organisms break down complex organic matter into inorganic matter. These are extremely important parts of the ecosystem because they recycle all the dead matter back into the earth.

Fungi and bacteria are two forms of decomposers. They break down anything which is dead, from a producer to a consumer.

Click here for a test on food chains and food webs

Click here for a worksheet on Food chains and Food webs

Click here for a Rock Pool Assessment


1. What is the link between food chains and energy? (1 mark)

2. Observe the food web bellow, list 3 food chains (3 marks)

3. Define an Ecosystem (2 marks)

4. Define what a community is (1 mark)

5. Explain 3 relationships between animals, and state how each of them benefits or is harmed (6 marks)

6. Explain how toxic materials have greater effects on top predators in a food chain

7. Explain why different organisms are needed in an ecosystem

8. Define a Niche