Food Web Lab
Materials: Food Web Activity Cards, Ball of String, and Tape
Follow your teacher’s directions to form a circle with your classmates. Your teacher will read a description of an ecosystem. You and your classmates will create a food web to trace the energy flow through this ecosystem.
Your Organism
1. Your teacher will hand you a card that contains information about one type of organism in the ecosystem. Take a minute to read the card and get familiar with the information.
2. Answer the following questions:
a. What is the common name of your organism? ______
b. What kingdom does this organism belong to? ______
c. How does your organism obtain energy______
(producer, consumer or decomposer)?
d. Define producer, consumer, and decomposer in your own words.
Producer: ______
______
Consumer: ______
______
Decomposer: ______
______
d. Does your species have any predators? ______
Food Web
1. Now you are going to create a food web with all your classmates! Follow the steps below.
a. Your teacher will give the ball of string to one person.
b. The person with the string reads the name of his or her species, how the species obtains food or energy, and what eats this species (if anything).
c. Next, this person holds one end of the string and then tosses the ball to one of his/her prey (or energy source).
d. The string should form a line between the two species. Still holding that line, the prey tosses the ball back to the predator. Now there is a “loop” connecting the two species.
e. If there are additional prey species, the predator should repeat this sequence with each one.
f. When the predator is finished, he or she should hand the ball of string to the teacher. The teacher will pass the ball on to the next student who will continue the process. Keep going until all the members of the food web have been accounted for. Keep the string tight between students so that relationships are not lost!
A change in balance!
1. A disease attacks one of the species in your food web. The entire population of this species is destroyed. You will draw straws to determine which species is affected. Do NOT drop your string.
2. All members of the affected species must drop the string and take one step back from the web.
3. As a class, discuss what happened to the string when this species disappeared. How does this model what happens to energy flow in the food web?
4. Roll up the ball of string.
5. Return your desk with your species card.
6. Answer the questions in the next section.
Food Chain
1. The teacher will ask one of the producers to come put their card on the board with tape. Next, the producer will choose one of his or her consumers to put their card next. The second student will place their card on the boar and choose one of his or her consumers to come up. This is repeated until a card with no predators or consumers is on the board. This represents a food chain.
2. Sketch the food chain the class created below.
Energy Pyramid
1. The teacher will guide you in building several energy pyramids. Choose one to sketch.
2. Define energy pyramid in the space next to the pyramid after sketching yours.
3. Use the space below to explain why each tier of the pyramid gets smaller as you move toward the top.
Thinking About What You Observed
1. These questions should be completed individually at the conclusion of the investigation.
a. What species did you represent in the investigation?
b. Were you a producer or a consumer? If you were a consumer, what kind were you? Explain your reasoning.
c. A deadly disease kills off the species that you represented in the food web. Identify three other organisms in the food web that would be affected by this loss. What would happen to them?
d. What would happen to the food web if all of the plant species were sprayed by chemicals and killed? Explain your reasoning.
e. Why is it crucial that both predators and prey live in an ecosystem? Explain your reasoning.
f. This investigation did not include any decomposers. What is an example of a decomposer? What would its role be in an ecosystem?
Adapted from CPO Life Science 2008