Lesson Content

• Lesson Plan Template:

  Learning Cycle (5E Model)

• Learning Objectives: What will students know and be able to do as a result of this lesson?

  
  
  • Students will demonstrate and explain that living systems obey the the law of conservation of mass.

   

• Prior Knowledge: What prior knowledge should students have for this lesson?

  
  
  • Students should have some knowledge of habitats and and of organism roles in an ecosystem (producer, consumer, decomposer).
  • Students should be familiar with the term trophic level. Additionally, they should understand that food contains energy and that sunlight drives food production in photosynthetic organisms.
  • Students should be familiar with the Law of Conservation of Mass and Energy - energy is neither created nor destroyed, it just changes form.
  • Students should be able to measure volume with a graduated cylinder.

   

• Guiding Questions: What are the guiding questions for this lesson?

  
  
  1. How does energy flow in a food web or food chain?
     • Energy flows in a food web by being transferred to and between organisms as they undergo photosynthesis, are consumed by other organisms, or decompose.
  2. How can energy move throughtrophic levels?
     • Energy moves through trophic levels when an organism is eaten by another or dies and decomposes.

   

• Engage: What object, event, or questions will the teacher use to trigger the students' curiosity and engage them in the concepts?

  
  
  1. Pass out Energy Transfer Lab Packet (attached). Provide one packet per student.
  2. For the first 15 minutes of class students should read through the Problem Statement on the first page and complete the first three responses (three facts they already know about energy in an ecosystem). Students can then share their responses with the class.  
  3. This will get students thinking about ecosystems and why organisms need energy. Some topics that can be brought up through the class discussion are organisms roles in an ecosystem, food chains and food webs, and photosynthesis.

   

• Explore: What will the students do to explore the concepts and skills being developed through the lesson?

  
  
  1. Students will investigate a model of energy flow in an ecosystem using the transfer of water from cup to cup. Divide the class into groups of 6 and instruct the students to complete the first three pages of their Energy Transfer Lab Packet (hypothesis, data table, graph).
  2. To guide discussion and to assess students during their work, the teacher may ask student groups any of the following questions while walking around the room checking on their progress.
     • How does energy flow through a food chain or food web?
       • Energy flows in a food web by being transferred to and between organisms as they undergo photosynthesis, are consumed by another organism, or decompose.
     • Where does the energy of a food web come from?
       • Energy enters the food web through photosynthesis from the sun.
     • How can energy move throughtrophic levels?
       • Energy moves through trophic levels when an organism is eaten by another or dies and decomposes.
     • What are producers, consumers, decomposers?
       • Producers are organisms that can make their own food. Consumers must digest other organisms to survive. Decomposers are similar to consumers but their food sources are primarily dead at the time of consumption.

   

• Explain: What will the students and teacher do so students have opportunities to clarify their ideas, reach a conclusion or generalization, and communicate what they know to others?

  
  
  1. The fourth page of the Energy Transfer Lab Packet provides a list of questions. Students will work in their groups to answer the reflection and extension questions and record their responses. The teacher will then lead the class in a group discussion of their responses.
  2. Some of the key points to address once students are done with the investigation include:
     • Plants get energy from the sun through photosynthesis
     • All energy in an ecosystem originates at the first step in the food chain or web
     • In order for an animal to get energy, it must eat another organism
  3. Common misconceptions that students may have:
     • Students may not realize that energy enters the ecosystem via the sun
     • Ecosystems follow the Law of Conservation of Mass and Energy
     • Energy is transferred from one organism to another and is used for life functions such as reproduction, growth, maintaining body heat...

   

• Elaborate: What will the students do to apply their conceptual understanding and skills to solve a problem, make a decision, perform a task, or make sense of new knowledge?

  
  
  1. The last page of the Energy Transfer Lab Packet provides an opportunity for students to elaborate on what they have learned. The teacher will instruct students to draw a food chain and label each organism. They will then list 3 ways in which that organism uses energy. The teacher should prompt students to conclude that 100% of the energy isn't transferred on to the next level because it is used by the organism.
  2. The teacher should check student drawn food chains to be sure they have listed ways in which each organism uses energy. If time allows, students can present their food chain to the class or students can work in small groups to ensure all information on the food chain is correct.
  3. Students may have difficulty creating a food chain, the teacher can walk them through each trophic level using a local or familiar ecosystem as an example.
  4. If students have difficulty coming up with ways that organisms use energy, the teacher can help direct them by talking about things they do each day to survive, discussing what an organism needs in order to live or talking about how individual organisms help ensure the survival of their species through reproduction. Ex: A grass might use some of the energy it produces to make seeds. If the seeds disperse and the grass is eaten by a bison, the energy used to produce seeds is not consumed by that animal.
  5. To wrap up the lesson, the teacher will then ask the class to use evidence from the discussion and lab activity to answer the following question: How does a food chain follow the Law of Conservation of Mass and Energy?
     • Possible responses include: energy only enters an ecosystem at one point.
     • Energy is not lost during its movement through an ecosystem, it just changes form.
     • Energy is obtained from the trophic level below and is used to produce heat and provide energy for the organism to perform functions such as growing, reproducing and movement.

   

• Summative Assessment

  
  
  • The Energy Transfer Lab Packet can be collected and the data table, graph, responses to the questions, and/or food chain diagram graded. An answer key is attached.
  • The final discussion question could also be given as an exit slip.

   

• Formative Assessment

  
  

  To guide discussion and to assess students during their work, the teacher may ask any of the following questions while walking around the room checking on each group.

  • How does energy flow through a food chain or food web?  

  • Energy flows in a food web by being transferred to and between organisms as they undergo photosynthesis, are consumed by another organism or decompose.

  • Where does the energy of a food web come from?

  • Energy enters the food web through photosynthesis from the Sun.

  • How can energy move through trophic levels?

  • Energy moves through trophic levels when an organism is eaten by another or dies and gets decomposed.

  • What are producers, consumers, decomposers?

  • Producers are organisms that can make their own food.  Consumers must digest other organisms to survive.  Decomposers are similar to consumers but their food sources are primarily dead at the time of consumption.

  Class discussion throughout the lab and during the Explain section also provides formative assessment opportunities.

   

• Feedback to Students

  
  

  Specific suggestions for providing Feedback to Students can be found in the Explore, Explain and Elaborate phases of the lesson where it says, "Common errors/misconceptions to anticipate and how to respond."