1. Living Systems
Investigation 1, Part 4 –
Recycling

2. Reviewing Food Webs
Which organisms in the woods ecosystem food web are producers, which are consumers, and which are decomposers? Why do animals eat other organisms?
Living Systems, 1.4: Recycling
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3. Consumers Animals that eat plants only are primary consumers.
Animals that eat primary consumer animals are secondary consumers.
Animals that eat plants and animals are third-level consumers.
Animals at the top of the food web are top consumers. They are rarely taken and eaten for food.
Living Systems, 1.4: Recycling
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4. Decomposers
What happens to the system when the top consumers and individual members of other food levels are not eaten? What happens to organisms that are not eaten by other animals when the organisms die?
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Step 2

5. Decomposers
The organisms that clean up the ecosystem are called decomposers. There are two groups of decomposers:
Grinders
Finishers
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Step 2

6. Compost Worms
Compost worms live in the ecosystem in the space between the soil's surface and the top of the layer of leaf litter.
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Step 2

7. Focus Question
What happens when compost worms interact with organic litter?
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Step 3

8. A Redworm Habitat Put about 1 to 2 cm of garden soil in the jar.
Tear two sheets of newspaper into strips and moisten the paper.
Fill the jar with the damp newspaper strips until it is almost full.
Add some natural leaf litter and a small amount of fresh household waste.
Once everything is in the jar, screw on the lid and give the jar a good shake—but not a violent shake—to mix the contents.
Moisten the contents if needed.
Count 15 to 18 redworms and put them into the container.
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Step 4

9. Blocking the Light
In their natural habitat, worms live under layers of dead leaves where it is dark.
Create a light barrier on the worm habitat.
Open a black plastic bag.
Place the worm habitat in the bag.
Draw the mouth of the bag around the neck of the jar.
Secure the mouth of the bag with a rubber band.
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10. The Worm System Is the worm habitat a system? Why or why not?
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11. The Worm System
Write a list of the parts of the system in your notebook. How is your worm habitat like a subsystem? What do you think will happen in your worm habitat? What questions do you have about this system?
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12. The Worm-Habitat System
What are the parts of the worm-habitat system?
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13. Focus Question
What happens when compost worms interact with organic litter?
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14. Vocabulary Review
compost decaying organic material redworms worms that are decomposers. They are grinders.
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15. Reading in Science Resources
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Steps 14–16

16. Food Webs
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Step 17

17. Wrap-Up
Use your three self-stick strips to mark the three most important things you've learned in this investigation. Use a highlighter or colored pencils to highlight key points. Discuss in your groups the ideas you have marked.
What are the key points in this investigation?
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Step 18

18. Investigation Guiding Question
How does matter and energy move through ecosystems of the biosphere?
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Step 19

19. All rights reserved. Copyright The Regents of the University of California.
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Photo credits:
Cover slide: © photovideostock/Shutterstock
Notebook image: © photastic/Shutterstock TM
Living Systems, 1.4: Recycling