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FOOD CHAINS AND FOOD WEBS

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					                             FOOD CHAINS AND FOOD WEBS

Using the information from the following website and your own knowledge, complete the
activities below to further your understanding of food chains, food webs, and the roles that
organisms play within an ecosystem.

1. Open the computer’s internet browser and type in the following URL.
      http://www.vtaide.com/png/foodchains.htm

?   What are four reasons why living things need energy? From where do organisms get energy?




?   What is a food chain?



?  Why is the food chain shaped like a pyramid? Use a quotation from the reading to support
your answer.




? What is a food web? Draw a 3-link and a 4-link food chain from the diagram provided on the
website.




2. Read the paragraph about how a change in the size of one population can affect other
populations in the food chain.

?   Describe an example of feedback within the savannah ecosystem.




3. Click on “Chain Reaction Activity” and then click on “Start”. Work your way through
the activity in order to answer the following questions.
? Why are people, in general, known as omnivores?
?  What is the difference between herbivores and carnivores? Give examples to support your
answer.




?  Why do food chains always begin with a producer? What process do plants use to make
food?




4. Complete the food chain activity and click on “Test the FOOD CHAIN” when you think
you have the correct sequence. After the animation is complete, fill in the organisms of the
food chain below.




?   What does the direction of the arrow represent?




?  What do you think will happen if frogs are removed from the food chain? Write a prediction
about changes in two other populations or organisms within the food chain.




5. Test your prediction by clicking on the frog.

?   Record two other possible effects of removing the frogs from the food chain.
?  Would removing all of the grass or removing all of the snakes be more harmful to the
community? Justify your answer.




6. Click on “Close Window” at the bottom of the window.

7. Scroll back up next to the food web diagram and click on the “creating a possible food
web” link.

8. Scroll to the bottom of the page and click on the “Arctic Food Web” link.

9. Fill in the Arctic Food Web and use the completed food web to answer the following
questions.

?  List the organisms in the arctic food web and classify them according to their role in the
environment (carnivore, herbivore, omnivore, or producer).




10. Close the “Arctic Food Web” window.

11. Click on the “Meadow Food Web” link and complete the Meadow
Food Web by dragging the organisms into their correct positions.

?   A homeowner is concerned that the foxes near his home will prey upon his five pet cats who
like to spend part of their time outside. He wants to hire someone to trap and remove as many
foxes from the meadows surrounding the neighborhood as possible. In a paragraph, explain to
the homeowner how removing all the foxes would affect the meadow food web and why this
might cause other problems for the homeowner. Be sure to include vocabulary to strengthen
your position.
12. Close the “Meadow Food Web” window and then close the “Create a Food Web”
window.

13. Scroll to the bottom of the Food Chains and Webs page and click on “Food Chains
MCQ”.

14. Answer the multiple choice questions by clicking on the button of the correct answer.

15. Once you have answered all of the questions correctly, print the page so that you can
turn it in with this worksheet.

16. Go back to the third question and click on the “detritivores” answer button.

?   Write a description of a detritivore below. Give an example to support your answer.




? Give two examples of decomposers. How are decomposers important to food chains and food
webs?



?   Raccoons and hyenas will feed off the carcasses of dead animals. What ecological role does
this describe?




EXTENSION

Construct a food web for a biome of your choice. Your food web should include a minimum of
10 organisms, at least three of which should be producers. Use the names of specific organisms
to construct your web, as opposed to more general terms such as “bird” and “tree”.

				
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posted:11/30/2011
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