1. Roles in an Ecosystem
SPI Classify organisms as producers, consumers, scavengers, or decomposers according to their role in a food chain or food web.

2. Definitions
Producer - an organism that makes its own food from non-living materials
Consumer - an organism that eats other living things for energy
Scavenger - an organism that quickly consumes and breaks down dead organisms or waste matter into smaller substances
Decomposer - an organism that absorbs (consumes and breaks down) dead organisms or waste matter into simple chemical substances

3. Check for Understanding
Which role must get energy from the sun to make its own food?
Which role must absorb energy from dead organisms?
Which role must take in energy from other organisms?
Which role quickly consumes and breaks down dead organisms?

4. Answers
Producers
Decomposers
Consumers
Scavengers

5. Producers
The organisms that produce food are extremely important in every ecosystem because this is where the energy begins in an ecosystem.
Organisms that produce their own food are called producers.
There are two ways of producing food energy:
Photosynthesis: plants on land, phytoplankton in the surface ocean, and some other organisms.
Chemosynthesis: bacteria at hydrothermal vents on the ocean floor.

6. Check for Understanding
Producers are always the ______ step in a food web or food chain.
Define a producer in an ecosystem.
What process do plants use to produce energy?
What process do phytoplankton use to produce energy?
What is an example of an organism that uses chemosynthesis?

7. Answers First, beginning
Producers are organisms that make their own energy.
Photosynthesis
Bacteria at hydrothermal vents on the ocean floor use chemosynthesis.

8. Consumers
Organisms that use the food energy that was created by producers are named consumers.
There are many types of consumers:
Herbivores eat producers directly. These animals break down the plant structures to get the materials and energy they need.
Carnivores eat animals; they can eat herbivores or other carnivores.
Omnivores eat plants and animals as well as fungi, bacteria, and organisms from the other kingdoms.

10. Check for Understanding
How do consumers get their energy?
What kind of consumer only eats producers?
What kind of consumer eats both plants and animals?
What kind of consumer eats herbivores?
What kind of consumer are you?

11. Answers
From eating other organisms
Herbivores
Omnivore
Carnivore

12. Video Clip on Producers & Consumers (3:13)

13. Decomposers
Decomposers break apart dead organisms or the waste material of living organisms, returning the nutrients (chemicals) to the ecosystem.
Consumers of all types, as well as primary producers, produce waste, and eventually, they perish.
Include types of bacteria, fungi, worms and more.
Decomposers are the final actors in the movement of energy through an ecosystem.
During the decomposition process, all energy remaining in the ecosystem is released as heat, which then disperses. This explains why compost piles and garden mulch tend to emit heat.

14. Check for Understanding
Why do ecosystems need decomposers?
What are some examples of decomposers?

15. Answers
Without decomposers the nutrients (chemicals) in an ecosystem could not be recycled.
Bacteria, fungi (mushrooms), worms, beetles, centipedes, etc.

16. Video Clip on Decomposers (3:18)

17. Scavengers
Scavengers, including coyotes, crows and ravens, vultures and many other species of animal, play a major role in maintaining a healthy habitat.
Dead animals are a health hazard to living animals, as they can spread disease -- but scavengers quickly break down the dead biomass, and everyone in the ecosystem benefits. 

18. Check for Understanding
How are scavengers different from decomposers?
Why are scavengers important in an ecosystem?
What are some examples of scavengers?

19. Answers
Scavengers break down dead organisms much faster than decomposers.
Quickly breaking down dead organisms prevents disease
Examples include coyotes, hyenas, crows, ravens, vultures, condors, hagfish, flies, etc.

20. Name the Roles for these organisms

21. Answers Producer Grass Trees Bushes Flowers Consumer (everything else)
Decomposer
Worms
Slugs
Beetles
Wood lice

22. Name My Role
Producers, Consumers, or Decomposers?

23. Answer
Sheep are consumers.

24. Name My Role
Producer, Consumer, or Decomposer?

25. Answer
Sunflowers are producers.

26. Name My Role
Producer, Consumer, or Decomposer?

27. Answer
Grasshoppers are consumers.

28. Name My Role
Producers, Consumers, or Decomposers?

29. Answer
All of these insects are decomposers.

30. Name My Role
Producers, Consumers, or Decomposers?

31. Answer
Both the fish and the bear are consumers.

32. Name My Role
Producer, Consumer, or Decomposer?

33. Answer
Bacteria is a decomposer.

34. TCAP Practice Question 1

35. Answer B

36. TCAP Practice Question 2

37. Answer B

38. TCAP Practice Question 3
Name the producers in the food web.

39. Answer
Wheat and Clover

40. TCAP Practice Question 4
Which organisms are consumers?

41. Answer
Insect, Rabbit, Bird, and Fox

42. TCAP Practice Question 5

43. Answer C