Lesson: Using Cooperative Learning to Investigate the Flow of Matter and Energy in an Ecosystem
This lesson attempts to prompt discussions of the following misconceptions:
1) Food is energy--energy is stored in the chemical bonds that hold the atoms that compose food together. Food itself is not energy.
2) All of the energy from a plant or animal is passed on to what eats it--only a small percentage of energy is passes onto the predator. Most of the energy is used for the organisms life functions prior to being consumed. Additionally, life functions lead to the energy being transformed into thermal energy and given off as heat. Therefore, not all of the energy is passed onto the predator. Note: read about thermodynamics
3) Plants want to be eaten--Plants exist because they are living things. All living things require energy to do work. Producers (autotrophs) have the unique ability to convert UV radiation, carbon dioxide and water into glucose. They make energy to support their own survival, not because the want to feed other organisms. Without their existence however all living things would not exist.
Do Now (Option 1): Why do organisms eat?
This prior knowledge question asks students to think about why organisms eat. You will gauge their present level of understanding of matter and energy acquisition to do work and grow.
Do Now (Option 2): Use clicker technology to pre-assess student understanding of matter and energy flow. See resources--will be posted soon.
Once you have done this, briefly instruct students on food chains, food webs and trophic levels. Chances are that by middle school your students will have significant exposure to food chains, but they will have limited understanding of how food webs relate to the conservation of matter and energy. Giving them background information on food chains, why the arrows point the way they do, food webs and trophic levels will assist in making the cooperative learning portion of the lesson to flow more smoothly.
Desks should be separated into groups of 4-5 students.
Give instructions of how the activity will work:
1) Each group will be given one of the 6 readings. Note: part 6 has students apply their understanding of food webs by asking them to read about the specific role of different organisms to determine where they would fit into a web.
Each student will get an opportunity to read a passage that pertains to a specific 'part' on their 'Energy Flow Student Notes WS' (see resources). Students will then work together in their cooperative learning groups to answer the follow-up questions at the conclusion of each reading.
Each group should get around 5-8 minutes. It's okay if they don't have enough time to finish each question; they will finish the rest at the end of class or the following day. It's better to have too much work to do than not enough....
2) After time has expired, groups should pass counter clockwise to the next group. Emphasize the importance of noting the 'Part' number noted at the top of each reading. This will guide them when answering the correct follow-up questions.
3) Repeat until all groups have read and attempted to answer each question.
Teachers should circulate around from group to group in order to gauge student understanding and address misconceptions as they arise. In addition, you should check for understanding by asking prompting questions about various trophic levels, what the Laws of Conservation of Mass and Energy state and how they apply to photosynthesis, decomposition, etc.
|NSTA SCIENCE SCOPE ARTICLE.PDF||
|Energy Flow Student Notes Worksheet.doc Classwork||
|Energy Flow Food Web.doc Classwork||
|Energy Flow Part 6.doc Classwork||
|Cooperative learning group readings.doc Reading Passage||