Feeding relationships in an ecosystem

1. Feeding relationships in an ecosystem IGCSE Biology

2. Feeding types Organisms 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.

3. Can you sort out the following organisms into producers and consumers?

4. Consumers Consumers 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.

5. Can you sort out the following into herbivores, carnivores and omnivores?

6. Food chains A food chain is a sequence which shows how each individual feeds on the organism below it in the chain. Each arrow means ‘eatenby’. leaf caterpillar 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.

7. Producer, herbivore orcarnivore? Food chains always start with a producer. The source of energy for all food chains is always the sun 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. From a food chain, we can tell if an organism is a producer, a herbivore or a carnivore. leaf snail bird owl What are the feeding types of the animals in this food chain?

8. seaweed limpet crab human Ranking consumers Consumers eat plants or animals, or both. A food chain can be used to rank different types of consumers. producer primary consumer secondary consumer tertiary consumer • Producers – make their own food. • Primary consumers – eat producers. • Secondary consumers – eat primary consumers. • Tertiary consumers – eat secondary consumers.

9. Group challenge Can you use as many of these terms you have met correctly in labelling the following food chain? Primary consumer Producer Secondary consumer Tertiary consumer Green plant HERBIVORE CARNIVORE TOP CARNIVORE If it also eats seeds and nuts it would be an Arrows show energy flow OMNIVORE

10. Now try yourfoodchains!