5. Food Chains - Lesson Plan
- Begin the lesson with the question: “What did you eat for dinner last night?" Break responses down into individual ingredients (separate lasagna into pasta, beef, tomatoes, and cheese) and write them on the board.
- Once you have a broad sampling, begin categorizing the ingredients into producers, and consumers. Use questions such as:
- Which of these foods come from plants?
- Which of these foods don't come from plants? (If mushrooms are on the board, remember that technically mushrooms are fungi not plants!)
At this point, introduce the idea of producers as plants, or more scientifically, as organisms that make their own food through photosynthesis. Introduce the idea of consumers as animals, or more scientifically, as organisms that eat producers or other consumers.
- Break down the consumer category further into herbivore, carnivore, omnivore, and dentritivore (or decomposer). Use questions such as:
- Of the consumers, which are animals that eat plants?
- Which are animals that eat other animals?
- Which eat both?
- Are there any decomposers? (Mushrooms, crab, shrimp, and lobster are likely to be the only decomposers.)
Introduce the vocabulary words herbivore, carnivore, omnivore, and dentritivore at this point and give the formal definitions.
- Ask students to describe a food chain. As part of this discussion, try to follow one or more of the foods on the board through the food chain. For example, sun -> corn -> cow -> people. All the food chains we will be dealing with in this class have the sun as the initial energy source although you may want to briefly mention the existence of other food chains that do not depend on the sun (see notes in Teacher Background section).
- Introduce today's activity. Students should receive a set of organism cards. Their first task is to color code the organisms on their cards by their role in the food chain. Write the color code up on the board: green = producers, yellow = herbivores, red = carnivores, orange = omnivores, blue = dentritivores.
- When students begin to finish color coding, have students cut out their cards and begin to organize them into food chains. Definitely tell them that there are multiple food chains. If you want, you can tell them how many. When students have identified a complete chain, they can glue it down on a piece of notebook paper.
- With 10 minutes before the end of class, have students stop and clean up. Any work they have remaining can be assigned as homework. Envelopes can be used to contain any cut out cards that have not been glued down yet. In my classes, about 50% had finished the activity at this point. 50% had to bring home work to finish at home.
- Once the students have cleaned up and are settled again, put the food pyramid up on the overhead and ask students what they think the picture represents. They should recognize the pictures from their food chain activity. Ask the students why there are more grasses than rabbits and why there are more rabbits than bobcats. Discuss the transfer of energy from one level of the food chain to the next, focusing on how any one organism can't transfer the energy it gets from its food directly to the next organism in the food chain because it needs to use some of that energy itself to grow, reproduce and survive.
Submitted by irene on Fri, 2005-08-26 15:44