Eastern Intermediate High School Name:______
Accelerated Environmental Science 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
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.
MY FOOD CHART
Food(What you ate yesterday) / Components
(What’s in the food?) / Origin of Component (Organism)
Example: / Ham / Pig
Ham, Cheese, / Bread / Wheat Plant
and Mustard Sandwich / Cheese (Dairy) / Cow
Mustard Seeds / Mustard Plant
FOOD WEB DATA TABLE
Organism(Copy From “Origin of Content” in the MY FOOD CHART) / Energy Source of the Organism / What eats the organism in the 1st Column?
Example: Pig / Corn and Wheat / Weasels and Humans eat Pigs
1
FOOD WEB
BIOGEOCHEMICAL CYCLE
1
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
1