Food Chain Role Play

Transcription

1 Food Chain Role Play This simulation shows students how plants use energy from the sun to create carbohydrates during photosynthesis. Then students act out the flow of energy from one organism to another as consumers eat plants (and are in turn eaten by other animals). This role play helps students see how all of the energy in animals food originated from the sun. Next Generation Science Standards: 5-PS3-1. Use models to describe that energy in animals food (used for body repair, growth, motion, and to maintain body warmth) was once energy from the sun. 5-LS2-1. Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment. Materials: game cards, large bag of Skittles candy or 4 sheets of carbohydrate cards, zip-top sandwich bags and paper cups (one for each child in the class) Preparation: 1. Print one sheet of animal cards (6 caterpillars, 3 sparrows, and 1 cat) and four sheets of plant, water, and energy from the sun cards. 2. Print carbon dioxide and oxygen cards back-to-back, so the cards say carbon dioxide on one side and oxygen on the other. 3. Print several copies of the carbohydrate cards OR use Skittles candy to represent carbohydrates created during photosynthesis. 4. Put 10 Skittles in each paper cup. (For a food-free option, put 10 carbohydrate cards into each cup.) Set cups aside until they are needed. Attach an energy from the sun card to each cup of candy.

2 Procedure: 1. Have students stand or sit in a large circle. 2. You may choose to have one or two children act as Mother Nature and give them the job of distributing cards as you explain the process. 3. Give 75% of the students in the class a plant card, and give the other 25% a caterpillar card. Give each student a zip-top sandwich bag. 4. Ask students what plants need to survive. Answers may include air, soil, space, water, and sunlight. Remind students that while plants get some nutrients from the soil, plants can live without soil if sufficient nutrients are dissolved in their water. Explain that plants use energy from the sun, carbon dioxide from the air, and water to make their own food in a process called photosynthesis. 5. Ask students what materials the plant needs to photosynthesize (carbon dioxide, water, and sunlight). 6. Give plant students a carbon dioxide card and a water card to place in their plastic bags. Remind students that plants must have these materials to survive, but they cannot do anything with these materials without the energy to do so. Where does this energy come from? The sun. 7. Give the plants a cup labeled energy from the sun. Light gives plants the energy they need to photosynthesize. Using this energy, plants can transform the carbon dioxide and water into carbohydrates (sugars) and oxygen. Have students remove the water and carbon dioxide cards from their bags and pour in the Skittles or carbohydrate cards. Students can toss the oxygen cards in the air as they take them out of the bags to show that this oxygen is released back into the air.

3 8. The plants now have 10 Skittles to represent the carbohydrates created during photosynthesis, but what about the caterpillars? Caterpillars are animals that must eat food, so they are consumers. They consume food energy created by the plants. 9. Before the caterpilars can eat anything, though, the plants must use some of the energy they stored as carbohydrates to grow and survive. Let plants eat 9 of the 10 Skittles from their bags. (If using carbohydrate cards, students can remove them and pretend to eat them.) 10. Now the caterpillars can go and eat the plants, getting the remaining Skittle from the plants. Caterpillars will likely complain that they did not get as many Skittles as the plants. Explain that this is because plants use most of the energy they get from the sun to make carbohydrates for their own survival. Only 10% of the energy they create is stored in the plant s structures to be passed to the consumer when the plant is eaten. Where did the energy to make the carbohydrates come from? The sun. So without the sun, the caterpillars would not have any energy at all. 11. Some caterpillars only ate one or two Skittles. What happens if an animal does not get enough food to live? It dies. How can we support a larger animal population? We need more plants. 12. Collect the cards and refill the cups with 10 Skittles as needed. Redistribute plant and animal cards so students have different roles in the food chain. This time, distribute 4 caterpillar cards, 2 sparrow cards, and 1 cat card. All other students get two plant cards each. 13. Tell students that the number of plants has doubled because we must have many more plants than animals on Earth. Since plants can harness energy from the sun and use it to produce chemical energy in the form of carbohydrates, plants are called producers. Organisms that must eat to obtain their energy, like animals, are consumers. Without a large number of producers, there is not enough energy for the consumers to use to survive.

4 14. Repeat the photosynthesis simulation, doubling the amount of energy (Skittles) produced during photosynthesis. Plants again use up (eat) 90% of the energy and only have 10% stored in the plant when they are eaten. 15. Caterpillars eat the plants, collecting Skittles in their bags as they do so. Before allowing the caterpillars to eat their Skittles, explain that the caterpillars are primary consumers because they are the first consumers to eat anything. The caterpillars use 90% of the energy they get from the plants to grow and survive, so let the caterpillars eat 90% of what is in their bag (leaving at least one Skittle in the bag). 16. The sparrows eat the caterpillars, taking the remaining Skittles from the caterpillars bags. Where did this energy stored in the caterpillars come from? The plants. And where did the plants get the energy? From the sun. 17. The sparrows will use 90% of the energy they get to grow, heal, move, maintain body temperature, and other life processes, so sparrows eat 90% of the energy (Skittles) they collect. The sparrows were the second organism to have to eat something to get energy to survive, so they are secondary consumers. 18. There is very little energy left for the cat! The cat collects the remaining Skittles from the sparrows and eats all but one. The cat is the third organism to eat something to get its energy, so it is a tertiary consumer. Why doesn t the cat eat all the remaining Skittles? It uses 90% of the energy it receives to survive, but the other 10% is stored in the cat s body. Even if nothing eats the cat, the energy stored in its body will still be passed on to decomposers when its body decays. Questions for discussion following the role-play activity: Why are there more plants and very small animals (such as insects) in the world compared to larger animals (like people)? What is the ultimate source of energy in all food?

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7 Caterpillar Caterpillar Caterpillar Caterpillar Caterpillar Caterpillar Sparrow Sparrow (Secondary Consumer) Cat (Secondary Consumer) Sparrow (Tertiary Consumer) (Secondary Consumer)

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9 Carbon Dioxide Carbon Dioxide Carbon Dioxide Carbon Dioxide

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