1. Food Chains and Food Webs
How energy moves in an ecosystem OR
who eats who!?

2. All things in ecosystem are either abiotic or biotic.

3. What is abiotic? Not associated with or derived from living organisms.
Abiotic factors in an environment include such items as sunlight, temperature, wind patterns, and precipitation.

4. What is biotic?
The living parts of the ecosystem, including animals, plants and microorganisms

5. Biotic factors are grouped by what each organism eats.
Biotic Factors: Biotic factors break down into several different types. Autotrophs are the producers, and they mainly include plants. Autotrophs form the base of the ecosystem, and they live in most environments. Saprotrophs are microorganisms called reducers or decomposers. These organisms help break down organic substances found in dead and decaying matter. Heterotrophs are consumers. (This group breaks down into two types, which are consumers and macroconsumers.) Consumers are animals that feed on other organisms. They are also referred to as phagotrophs, which means organisms that swallow or ingest. Macroconsumers are carnivores or herbivores. Herbivores, which are organisms that feed on plants, are called primary consumers. Carnivores that feed on herbivores are called primary consumers. Carnivores that feed on other organisms are called secondary consumers.

6. All of the energy in an ecosystem starts with the sun.

7. Producers use the sun to get energy and make their food through a process called photosynthesis.

8. Consumers have to eat producers or other consumers to get their energy.

9. Decomposers get energy from eating dead consumers and producers.

10. Organisms need this energy to live.
Energy moves through an ecosystem when one organism eats another organism.
This keeps the ecosystem going.

11. This energy pyramid is one way to show how energy moves
This energy pyramid is one way to show how energy moves. Producers are always at the bottom of the energy pyramid because they are the first things eaten. Notice that the amount of energy is lost, or decreases, as more organisms eat each other.

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

13. 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.

14. Food Chain Remember: Arrows are used to show where the energy is going.

15. Food Web Remember: Arrows are used to show where the energy is going.

17. Turn to you partner and tell them everything you know about food chains and food webs and what they show us about an ecosystem.

18. You could have mentioned that:
It shows use the way energy moves in an ecosystem.
It shows us who-eats-who in an ecosystem.
It is made up of producers, consumers and decomposers.
Arrows are used to show where the energy is moving.
……?

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

20. You could have said that:
A food chain shows one way energy moves in an ecosystem but a food web shows many ways energy moves.
A food web is made up of many different food chains.

21. Mouse Fox Owl Snake Berries Rabbit Squirrel Leaves Grasshopper Frog
Draw your own food web with the following organisms: ( Don’t forget to include arrows and remember that arrows show where the energy is moving.)
Mouse
Fox
Owl
Snake
Berries
Rabbit
Squirrel
Leaves
Grasshopper
Frog