Begin the lesson by giving students 10 minutes to complete the “What I THINK it means” column in the Food Web Vocabulary table (S-4-3-3_Food Web Vocabulary Table and KEY.doc). Once students have finished, fill in the “What it DOES mean” column with the entire class. Use the Internet to look for examples of each vocabulary word. Students can either write in answers, draw pictures, or print small pictures from the Internet to glue in the boxes. After they complete the Food Web Vocabulary table, have students complete the Feeding Habits Worksheet (S-4-3-3_Feeding Habits Worksheet and KEY.doc) to give them practice identifying animals that are omnivores, carnivores, and herbivores.
To provide real-world experiences, students will view videos about food chains and food webs. After viewing the videos, discuss the concept of food chains and how a food chain transfers energy from one animal to the next. First show Food Chains and Webs, and then one or more of the following videos:
- “Put Together the Chain” Activity
Write this list on the board: leaf, grasshopper, and frog. Help the class construct this food chain. Explain to students the transfer of energy from one animal to another.
“Scientists show the flow of energy on diagrams with arrows. The arrow always points to the organism that is eating the other. For example, when a crocodile eats a fish, an arrow goes from the fish towards the crocodile to show that energy flows from the fish to the crocodile when it is eaten.”
Write this list on the board: snake, rabbit, and berries. This time, have students work in groups to construct the food chain. Have students write their answers on a sheet of paper. Give students about 5 minutes; then ask volunteers to share the correct answer for the food chain.
Write this list on the board: grass, mouse, and fox. This time have students work independently to construct the food chain on a sheet of paper. After about 5 minutes, ask volunteers to share the correct answer for the food chain.
After explaining food chains to the class, explain to students that animals eat more than one thing, just as humans do. Have students look at the three food chains they have already constructed and see if they can find any other animals that can eat more than one thing. For example, foxes eat mice, but they also eat rabbits. Continue finding animals that eat more than one thing. After matching all the animals up, explain to students that this is a food web. As a class, finish putting the three food chains together into a food web.
Have students revisit and reflect on what they have learned by taking the class outside to observe for about 5 to 10 minutes. Have them bring a pencil, paper, and something to write on, like a notebook. Take students on a walk around the school building. Have students make a list of animals they see while walking. Also have students write down animals that they would expect to see outside or in a wooded area.
Back in the classroom, as a class construct a food web of all the animals the students wrote on their lists. Allow students to add additional animals to their list in order to complete their web.
When students have completed their food webs, get them involved in a station activity. Have students work in three groups. Rotate the groups every 15 minutes.
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Station 1: Place students in small groups and allow them to play games on http://www.harcourtschool.com/activity/food/food_menu.html to learn more about food webs. Students will have an opportunity to complete a meadow, arctic, and pond food web.
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Station 2: Have students complete the Food Web worksheet (S-4-3-3_Food Web Worksheet and KEY.doc). Encourage students to discuss what they believe to be the similarities and differences between food chains and food webs.
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Station 3: Have students complete the Food Web Construction worksheet (S-4-3-3_Food Web Construction Worksheet and KEY.doc). When students have finished their food webs, you can post them around the classroom. This activity gives students the opportunity to create a food web individually.
- After students complete the station activities, hand out a sticky note to each student. Ask students to write down a question they still have about food webs. They can place their written questions on the chalkboard. Before closing the lesson, read the questions and have the class answer as many questions as possible in the time remaining.
- Closing Activity
- Have students log on to the following Web site: http://www.nhptv.org/NatureWorks/nwepecosystems.htm. Allow students to work in small groups. Have students scroll down and read the paragraph under “Getting Along.” Have students work together to write a paragraph about how food chains and webs support the ecosystem. Make sure students include the three categories in an ecosystem. Students should also include some key points in each category.
Writing Rubric for Closing Activity
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Points
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Description
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2
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- Student fully explains how food chains/webs support the ecosystem.
- Student includes details for each of the three categories in an ecosystem.
- Student has excellent use of grammar and punctuation.
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1
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- Student shows some understanding of how food chains/webs support the ecosystem, but includes few or no details for each of the three categories in an ecosystem.
- Student has satisfactory use of grammar and punctuation.
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0
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- Student did not understand the prompt or attempt to answer the prompt.
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Extension:
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Have students choose an animal for which they will create a menu. Each menu should include an appetizer, entrée, and dessert they believe their particular animal would enjoy. The “dishes” should be animals that are part of their chosen animal’s food web. Encourage students to be creative and to have fun with the assignment. The menu can be typed or neatly handwritten and should include colored illustrations.
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Have students create a food web including decomposers.
