1. Energy and the Food Web
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2. Main Menu Food Chains vs. Food Webs Our Sources of Energy Producers
Pyramid
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Consumers
Test Your
Knowledge
(Quiz)
Decomposers
Practice
Questions

3. Where Do Living Things Get Energy From?
The sun provides the primary source of energy for life on earth.
Organisms also get energy from other plants and animals.
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Food Chains
vs.
Food Webs

4. Food Chains & Food Webs
Animals that eat plants for food may in turn become food for other animals. This sequence is called a food chain.
Most animals are part of more than one food chain and eat more than one kind of food in order to meet their food and energy requirements. These interconnected food chains form a food web.
The types of organisms involved in a food chain are producers, consumers (including herbivores, carnivores, omnivores, parasites, and scavengers), and decomposers.
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Watch a video
Producers

5. Producers
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Consumers
Plants are called producers because they are able to use light energy from the sun to produce food (sugar) from carbon dioxide and water.

6. Main
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Consumers
Herbivores
Many organisms can’t make their own food so they must eat plants and/or other animals. They are called consumers. There are several groups of consumers:
Herbivores
Carnivores
Omnivores
Parasites
Scavengers

7. Main
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Herbivores
Carnivores
Animals that eat ONLY PLANTS are called herbivores (or primary consumers).
Rabbits and giraffes are examples of herbivores.

8. Carnivores Animals that only eat OTHER ANIMALS are called carnivores.
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Animals that only eat OTHER ANIMALS are called carnivores.
***Think of them as meat eaters!
Carnivores that eat herbivores are called secondary consumers. (i.e. Wolves are carnivores that eat rabbits which eat plants.)
Carnivores that eat other carnivores are called tertiary consumers. (i.e. Killer whales eat seals which eat smaller fish which eat plankton.)
secondary consumer
Omnivores
tertiary consumer

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Omnivores
Parasites
Animals and people who eat BOTH animals and plants are called omnivores.
Human beings and raccoons are examples of omnivores.

10. Parasites Another type of consumer is a parasite.
Parasites are small organisms that live on the bodies of other organisms using up their energy.
Ticks are parasites that feed on animals such as deer.
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Scavengers

11. Scavengers Another type of consumer is a scavenger.
Scavengers eat the bodies of other dead animals.
Vultures are large birds that are scavengers.
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Decomposers

12. Main
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Decomposers
Example of
Food Chain
Decomposers feed on decaying matter and waste products, recycling nutrients back into the soil.
Many bacteria and fungi are decomposers.

13. Main
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Example of a Food Chain
Click for example
of a food web

14. Example of a Food Web
Watch video
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15. Main
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Check out this video!
Click on the following link to watch a short video clip about food chains and food webs:
* Be sure to read the interesting facts below the video. You may want to play the video more than once in order to read the captions below.
Food Chains
vs.
Food Webs
Transfer of
Energy

16. Transfer of Energy Through the Food Chain
As energy is transferred from one organism to another, the amount of energy available at the next level becomes less and less.
For example, when a herbivore eats, only a fraction of the energy (that it gets from plant food) becomes new body mass; the rest of the energy is lost as waste or used up by the herbivore to carry out its life processes (i.e., movement, digestion, reproduction). Therefore, when the herbivore is eaten by a carnivore, it passes only a small amount of total energy (that it has received) to the carnivore. Of the energy transferred from the herbivore to the carnivore, some energy will be "wasted" or "used up" by the carnivore. The carnivore then has to eat many herbivores to get enough energy to grow.
The further along the food chain you go, the less food (and hence energy) remains available. The food chain is an inefficient system.
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Energy
Pyramid

17. Energy Pyramid Food Chain carnivores herbivores Main Menu producers
This energy pyramid shows many plants providing food and energy to giraffes. As you go up, there are fewer giraffes than plants and even fewer lions than giraffes. As you continue along the food chain, fewer consumers exist. A large mass of living things at the base is needed to support a few at the top. Many herbivores are needed to support a few carnivores.

18. This food chain is inaccurate
because it doesn’t show the flow of energy in the correct order.
Energy
It should look like this…
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Next

19. This food chain is accurately illustrated
because it shows the flow of energy from the producer (which makes the food) to the largest, most complex consumer.
Primary consumer or herbivore
producer
Energy
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Tertiary consumer or omnivore
secondary consumer or carnivore
Practice

20. Grasshoppers, mice, rabbits, deer, beavers, moose, cows, sheep, goats and groundhogs only eat plants. What type of consumers are they?
Try again! Omnivores are consumers that eat both plants and animals.
A) omnivores
Excellent! Consumers that only eat plants are called herbivores.
B) herbivores
Try again! Carnivores are consumers that only eat other animals.
C) carnivores
Try again! Decomposers are consumers that feed on decaying matter and waste products.
D) decomposers
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21. Foxes, frogs, snakes, hawks, and wolves only eat other animals
Foxes, frogs, snakes, hawks, and wolves only eat other animals. What type of consumers are they?
A) omnivores
Try again! Omnivores are consumers that eat both plants and animals.
B) scavengers
Try again! Scavengers are consumers that eat the bodies of dead animals.
C) carnivores
Great job! Carnivores are consumers that only eat other animals.
D) decomposers
Try again! Decomposers are consumers that feed on decaying matter and waste products.
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22. Bears, turtles, monkeys, and squirrels eat both plants and animals
Bears, turtles, monkeys, and squirrels eat both plants and animals. What type of consumers are they?
A) omnivores
B) herbivores
C) carnivores
D) scavengers
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23. You are correct! Omnivores eat BOTH plants and animals.
Bears eat insects, fish, moose, elk, deer, sheep as well as honey, grass, and sedges.
Turtles eat snails, crayfish, crickets, earthworms, and also lettuce, small plants, and algae.
Monkeys eat frogs and lizards as well as fruits, flowers, and leaves.
Squirrels eat insects, moths, bird eggs and nestling birds and also seeds, fruits, acorns, and nuts.
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24. Try again! Herbivores are consumers that only eat plants.
This deer is a
herbivore.
Back to question

25. Try again! Carnivores are consumers that only eat other animals.
This snake is
a carnivore.
Back to question

26. Try again!
Scavengers are consumers that eat the bodies of dead animals.
This raven is
a scavenger.
Back to question

27. What is the largest group of organisms in a food chain, food web, or energy pyramid?
Try again! Decomposers are an important part but do not make up the largest group.
decomposers
Try again! There are less consumers than producers because there has to be more producers to support the consumers that eat other plants and/or animals.
B) consumers
C) carnivores
Try again! Because carnivores are higher up in the food chain, there are less of them.
D) producers
That’s right! Producers make up the largest group in order to sustain all of the other organisms that depend on them. They make the food that all other organisms consume.
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28. What are the herbivores in this food web?
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What are the herbivores in this food web?
Answer
the
question
here

29. What are the herbivores in the food web?
Look at
the food
web again
Try again! These organisms are producers. They make their own food.
A) grass & trees
Excellent! These organisms are herbivores. They eat the producers.
B) deer, rodents, birds, & insects
Try again! These organisms are secondary consumers which eat the herbivores.
C) foxes, owls, skunks, birds, & opossums
D) cougars and bears
Try again! These organisms are tertiary consumers which other eat carnivores, herbivores, and producers.
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30. Nice job with the practice questions!
Are you ready for the quiz?
Yes, I’m ready!
No, I want to
review more.

31. What is the primary source of energy for life on Earth?
A) the moon
B) the rain
C) the sun
D) the oceans
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32. Yes, that’s right! The sun is the necessary energy source for all life on Earth. Producers use light energy to make food, and all other organisms benefit from the sun’s energy indirectly through the food chain.
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33. Try again!
The moon does not provide life on Earth with energy. Think about what plants need to make food besides water and carbon dioxide. What kind of energy is it and where does this energy come from?
Back to question

34. Try again!
Rain does not provide life on Earth with energy. Think about what plants need to make food besides water and carbon dioxide. What kind of energy is it and where does this energy come from?
Back to question

35. Try again!
The oceans do not provide life on Earth with energy. They contain organisms that contain energy but aren’t the primary source of energy. Think about what plants need to make food besides water and carbon dioxide. What kind of energy is it and where does this energy come from?
Back to question

36. Bacteria and fungi are which of the following?
That’s correct! Bacteria and fungi are decomposers which break down matter and recycle nutrients back into the soil.
A) decomposers
B) producers
Try again! Producers make their own food. All plants are producers.
C) consumers
Try again! Consumers are organisms that consume plants and other animals.
D) carnivores
Try again! Carnivores are animals that only eat other animals.
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37. Which of these is NOT a producer?
Very good! A tiger is not a producer. It’s a carnivore because it eats deer, wild hog, peafowl, elephants, and buffalo.
A) a tiger
B) a fern
Try again! A fern is a producer because it’s a plant and therefore makes its own food.
Try again! A maple tree is a producer because it’s a large plant and therefore makes its own food.
C) a maple tree
D) grass
Try again! Grass is a producer because it’s a plant and therefore makes its own food.
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38. What do you call an animal that eats only plants and no meat?
A) a decomposer
Try again! A decomposer is an organism that breaks down dead matter and waste products.
B) a herbivore
Excellent! A herbivore is a consumer that eats only plants.
C) an omnivore
Try again! An omnivore is a consumer that eats BOTH plants and animals.
D) a carnivore
Try again! A carnivore is a consumer that eats only animals.
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39. What do you call an organism that eats both plants and animals?
A) carnivore
Try again! A carnivore only eats animals.
Great job! An omnivore eats BOTH plants and animals. Can you think of an example?
B) omnivore
C) herbivore
Try again! A herbivore only eats plants.
D) producer
Try again! A producer makes its own food using water, light energy, and carbon dioxide.
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40. As energy is transferred from one organism to the next, what happens to the amount of available energy?
Try again! Think about the energy pyramid. Try to picture it. Where is the most energy available and where is the least?
A) It increases.
Nice work! The energy pyramid shows that the most energy is at the bottom with the producers and as you go up to the top, the amount of energy decreases.
B) It decreases.
C) It stays the same.
Try again! Think about the energy pyramid. Try to picture it. Where is the most energy available and where is the least?
D) It increases then decreases.
Try again! Think about the energy pyramid. Try to picture it. Where is the most energy available and where is the least?
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41. What role do we humans play in our food web?
Try again! Humans can’t make their own food like producers can.
A) The role of producer
Excellent! Humans are consumers, specifically omnivores, because they eat plants and animals.
B) The role of consumer
Try again! Humans don’t feed on decaying matter and waste products like decomposers do.
C) The role of decomposer
D) The role of scavenger
Try again! Humans don’t eat the bodies of dead animals like scavengers do.
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42. How did you do on the quiz?
A) 0 questions wrong
Superb job! Keep up the great work.
B) 1 or 2 questions wrong
Good job! Review the questions you had trouble with.
C) 3 or 4 questions wrong
Keep practicing! Go back and review the questions you had trouble with.
D) 5, 6, or 7 questions wrong
Keep practicing! Go back and review the questions you had trouble with. Look back at the earlier slides for more information.
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FINISH!

43. Congratulations!
You completed this lesson on energy and the food web. Nice work!
You may either go back and review some of the concepts or exit the PowerPoint.
Keep up the great work! 
References
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44. References
Hazen, R. M. & Trefil, J. (1992). Science Matters. New York: Anchor Books.