Feeding relationship Herbivores Carnivores Omnivores Food chain Food web Biomass
Learning Intentions
In this topic we are learning to: zz
zz
Model the flow of energy through an ecosystem using a food chain and a food web.
Review the importance of decomposers to the cycling of key nutrients through the living and non-living parts of the Earth.
A feeding relationship is the way energy and nutrients are passed from one organism to another through an ecosystem.
z z zz
‘Biomass’
The quantity of matter in an organism is called its biomass.
The biomass of individual organisms increases as you move towards upper feeding levels in food chains. Predators are usually bigger than their prey.
Producers make their own food. For example, plants photosynthesise. Consumers must get their food by eating plants or other animals.
There are three types of consumer:
1. Herbivores are animals that eat plants only. For example, cattle and rabbits.
2. Carnivores are animals that eat animals only. For example, sparrowhawks and ladybirds.
3. Omnivores are animals that eat both plants and animals. For example, foxes and humans.
zz
Decomposers feed on dead plant and animal material. By breaking down this material, they recycle nutrients back into the soil. For example, bacteria, fungi and earthworms.
There are two ways to describe feeding relationships: zz
Food chain Food Chain
A food chain describes feeding relationships using arrows to show which organism eats another.
1. Food chains usually start with a plant, the producer.
Producer
Primary consumer
Secondary consumer
Tertiary consumer
2. The organism that eats the producer is the primary consumer. Primary consumers are usually herbivores.
