Food Chains Food Chains and and

Food WebsFood Webs

How energy moves in an ecosystemHow energy moves in an ecosystem

OROR

who eats who!?who eats who!?

All things in can ecosystem are either

abiotic or biotic.

Biotic factors are grouped by what each organism

eats.

All of the energy in an ecosystem starts with

the sun.

Producers use the sun to get energy and make their food through a

process called photosynthesis.

Consumers have to eat producers or other

consumers to get their energy.

Decomposers get energy from eating dead consumers and

producers.

Organisms need this energy to live.

Energy moves through an ecosystem when one organism eats another organism.

This keeps the ecosystem going.

This energy pyramid is one way to show how energy This energy pyramid is one way to show how energy moves. Producers are always at the bottom of the energy moves. Producers are always at the bottom of the energy

pyramid because they are the first things eaten. Notice pyramid because they are the first things eaten. Notice that the amount of energy is lost, or decreases, as more that the amount of energy is lost, or decreases, as more

organisms eat each other. organisms eat each other.

If we want to show the ways energy moves through an ecosystem we use a food chain or a food web.

Food Chain: A food chain shows one path of how energy moves through an ecosystem (who-eats-who).

Food Web: A food web shows many paths of how energy moves through an ecosystem (who-eats-who). A food web is made up of many different food chains.

Food ChainFood ChainRemember: Remember: Arrows are used to show Arrows are used to show

where the energy is where the energy is going.

Food WebFood Web Remember: Remember: Arrows are used to show Arrows are used to show

where the energy is where the energy is going.

Turn to you partner and tell them everything you know about food chains and food

webs and what they show us about an ecosystem.

You could have mentioned that:

1. It shows use the way energy moves in an ecosystem.

2. It shows us who-eats-who in an ecosystem.

3. It is made up of producers, consumers and decomposers.

4. Arrows are used to show where the energy is moving.

5. ……?

Now turn to your partner and discuss the difference between a food web and a food chain.

You could have said that:

1. A food chain shows one way energy moves in an ecosystem but a food web shows many ways energy moves.

2. A food web is made up of many different food chains.

DrawDraw your own your own food web food web with the following organisms:with the following organisms:

( Don’t forget to include arrows and remember that ( Don’t forget to include arrows and remember that

arrows show where the energy is moving.)arrows show where the energy is moving.)

Mouse

Fox

Owl

Snake

Berries

Rabbit

Squirrel

Leaves

Grasshopper

Frog