Eastern Intermediate High School
Accelerated Environmental Science
Name:___________________________
Mod:_______ Date:________________
Unit 3 – Ecology
Activity – Building a Food Web and a Nutrient Cycle
BACKGROUND
A food web is a diagram illustrating the feeding relationships between many plants and animals in a
certain area. They show the relationships between these organisms much more realistically than a
food chain. Food webs are very complex, linking many organisms together.
OBJECTIVE
In today’s activity you will create a food web based on the organisms you and your partner consume
to obtain energy. You will need to remember what you ate yesterday to complete your web. Use the
Internet to help find out where your food comes from and then make connections between yourself
and your environment.
PRODECEDURE
PART 1
1. Record all the items that you and your partner ate yesterday in the My Food Chart.
2. List the components of each food item in the chart. Use the Internet if needed.
3. Find the origin of each component (the organism it came from) and record that information in the
My Food Chart. Use the Internet if needed.
4. Transfer the Organisms (remember the Sun and any inorganic compounds such as water or salt
are NOT living organisms) in the My Food Chart into your Food Web Data Table.
5. Use your knowledge of the organism and the Internet to find the following:
a. The source of the organisms energy (ex. what it eats)
b. Other organisms that use the organism for energy (ex. who eats it)
c. Record the information in the Food Web Data Table.
6. Create a food web using the organisms from the 2nd and 3rd columns in the Food Web Data Table.
Your web must include at least:
a. 8 Autotrophs
b. 4 Herbivores
c. 4 Carnivores
d. 2 Omnivores
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7. Find images of the organisms on the web and paste them onto the Food Web page. Create
arrows to show the flow of energy. Each organism should be connected to at least one other
organism in the food web. The food web should be arranged in a hierarchy with autotrophs at
the bottom and tertiary consumers at the top.
Use the example below to help:
PART 2
8. For this part of the assignment you will create a diagram that shows the biogeochemical cycling of
one of the nutrients in your web. You may choose to show one of the following – The Carbon
Cycle, the Nitrogen Cycle and the Phosphorous cycle. Descriptions of each cycle are in the text
book.
9. Use your images from the food web and create new arrows to show the flow of matter through
your ecosystem. Paste them on the Biogeochemical Cycle page.
10. You should include abiotic factors such as water, air, and soil in your model.
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MY FOOD CHART
Food
Components
Origin of Component
(What you ate yesterday)
(What’s in the food?)
(Organism)
Example:
Ham
Bread
Cheese (Dairy)
Mustard Seeds
Pig
Wheat Plant
Cow
Mustard Plant
Ham, Cheese,
and Mustard Sandwich
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FOOD WEB DATA TABLE
Organism
(Copy From “Origin of Content” in
the MY FOOD CHART)
Example: Pig
Energy Source of the
Organism
What eats the organism
in the 1st Column?
Corn and Wheat
Weasels and Humans eat Pigs
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FOOD WEB
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BIOGEOCHEMICAL CYCLE
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ANALYSIS AND CONCLUSION
1. Ultimately, what supplies all of the energy required to support life in your food web?
2. Describe the flow of energy through your food web. In what order does energy move through
your food web? Where does it start? Where does it end?
3. At which level (group) does your food web contain the most energy?
4. What percentage of available energy is passed to the next trophic level in a food web? What
happens to the remaining energy? (hint: how is it used by the organisms in each trophic level?)
5. What is biomass? Contrast the way heterotrophs and autotrophs build biomass. Which
level of organisms on your Food Web had the most biomass?
6. What role would decomposers and detritivores play in your food web? Where would you
place them on the diagram?
7. In your web, which organism would be considered the keystone species? If you removed this
species from your food web, what effect might this have on the other organisms in your web?
Be specific; provide examples from your food web.
8. Describe the flow of matter through your Food Web.
9. This question is based on the WATER CONNECTIONS passage on page 100 in the Text. Using
your homework, explain why the introduction of invasive species in the great lakes altered the
natural food web.
10. Use the following link to read about the Japanese beetles impact. Explain how the beetle could
affect the food web you created with your partner.
http://en.wikipedia.org/wiki/Japanese_Beetle
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