Summary
This lesson introduces the idea of energy flow in ecosystems using energy pyramids. It also exposes students to a career in scientific illustration. Students participate in a game that models energy flow through trophic levels and calculate the transfer of energy up an energy pyramid. After learning about the career field of scientific illustration, students create an infographic that uses illustration to communicate each student's understanding of energy flow through food webs. While students will not explore it at a detailed level, it is recommended that students have familiarity with cellular respiration to help them connect their new learning to its context.
Essential Question(s)
How does energy flow through a food web? How is illustration used to convey scientific information?
Snapshot
Engage
Students brainstorm what plant and animal functions require energy and review respiration.
Explore
Students play an interactive energy pyramid game.
Explain
Students calculate the percentage of energy transferred in their game and develop an understanding of relevant science concepts.
Extend
Students explore the career of a scientific illustrator.
Evaluate
Students play the role of a scientific illustrator and create an infographic to explain what they’ve learned.
Materials
Lesson Slides (attached)
Energy Pyramid Game Cards (attached; one card per student)
Energy Pyramid Game Teacher Guide (attached)
Trophic level cards
Calculators (optional)
Chart paper
Printer paper
Sticky notes (optional)
Markers, colored pencils, etc.
Engage
Use the attached Lesson Slides to guide students through the lesson. Keep in mind that you can edit, add, or omit slides to suit class needs.
Using slides 2–4, introduce the lesson title, Essential Questions, and Lesson Objectives.
Display slide 5 and begin by having students use the Tell Me Everything strategy to brainstorm what they know about (1) cellular respiration and (2) the functions for which plants and animals use energy. This can be done independently, in small groups, or as an entire class directly on the board/chart paper.
As a class, discuss their ideas about how energy is used (e.g., growth, reproduction, hunting, digestion, blood circulation, etc.). Ask where the energy for these things comes from. Briefly review the function of cellular respiration with students. They will not be discussing the inputs and outputs in this lesson, but they should remember that respiration produces energy.
Explain to students that they will be exploring how energy flows through a food web of organisms in an ecosystem.
Explore
If students are not already familiar with the concept of trophic levels, take a moment to explain that trophic levels refer to organisms that occupy the same level in a food chain. If they are familiar already, ask for a volunteer(s) to explain what distinguishes different trophic levels from one another (e.g., primary consumers are herbivores, secondary consumers are omnivores or carnivores that eat herbivores, etc.).
Explain to the students that they will be playing a game that models how energy moves through trophic levels in an ecosystem. Specify that they are only tracing the energy used and passed on at each trophic level, not the amount of food being eaten. Refer them to the previous discussion about eating vs. producing energy.
Prepare students to play the trophic energy game. Review the Energy Pyramid Game Teacher Guide in advance for detailed setup instructions and facilitation details. Each student should receive one card cut out from the Energy Pyramid Game Cards handout. Students will need basic calculators to fill out the game cards. Go to slide 6 and review the instructions for how to fill out the cards. This slide is animated to illustrate each step so there is no ambiguity for the students.
Have students complete three rounds of energy exchanges where each student receives energy from the trophic level directly under them in an energy pyramid, or from the sun in the case of producers. Slides 7–9 have instructions for each round. Be sure to change the colors on the slide to reflect the colors you have used for each of your trophic levels.
Explain
Go to slide 10. After students have individually calculated their final energy at the end of Round 3 of the game, have them sum the final energy values for all the students in each trophic level. Next, have students calculate the percentage of energy transferred between each trophic level. The exact numbers will vary from class to class, depending on how students are grouped during the game, but it should be approximately 10% for each transition.
Go to slide 11. Ask students what they can conclude based on these results. Ask students to identify some of the limitations of the model (e.g., no omnivores; calculations at the scale of trophic levels, not the population levels where energy transfers occur).
Next, go to slide 12. Have students read a text over energy transfer in ecosystems and food webs. If you do not have a textbook with appropriate content, students can read the text and watch the videos in this CK-12 Flexbook: 6.4 Trophic Level.
Go to slide 13. Split the class into small groups of 3-4 students to complete the Strike Out strategy. They should not reference the reading or other class materials while trying to come up with their ideas, instead developing the big ideas from memory. Have groups share out their answers as a class and fill in any blanks they have in their conceptual understanding as necessary. Consider posting the students’ ideas in a public place for them to reference or copy down later.
Extend
Go to slide 14. Play the following videos for students as an introduction to the career of scientific illustration. The first video discusses what the job of a scientific illustrator entails and the second describes how a person can enter the field. Prompt students to think about what the experience of being a scientific illustrator would be like.
After watching the videos, go to slide 15. Ask students to use the Looks Like, Sounds Like, Feels Like strategy to imagine they are a scientific illustrator and describe what their career would be like. Students can put their answers on sticky notes and hang them up on the board or a designated chart paper for each of the three “…like” categories or record their ideas on their own paper. Ask students to share out some of their descriptions to get a sense of what the students took away from the videos.
Before moving on, go to slide 16. Ask students how scientific illustration might be important for the work they have been doing so far in the lesson. You may want to broaden this question to cover anything they have learned during the year if they are struggling to identify connections.
Evaluate
Go to slide 17. To wrap up the lesson, assign the role of scientific illustrators to students. Ask them to explain what they have learned during the lesson. Ask each student to create an infographic that communicates, both through illustrations and explanations, how energy flows through a food web/trophic level. They should include details about the following:
The sources of energy at different trophic levels of an ecosystem with specific emphasis on how energy is gained (i.e., through the breakdown of molecules that make up food);
The efficiency of energy transfer through an ecosystem; and
The ways energy is “lost” between trophic levels.
Time permitting, consider doing a Gallery Walk or have students share their infographics with the rest of the class in some other way.
Resources
Foundation, C. K.-12. (n.d.). 6.4 t
rophic level. CK. Retrieved January 30, 2023, from https://flexbooks.ck12.org/cbook/ck-12-biology-flexbook-2.0/section/6.4/primary/lesson/trophic-levels-bio/
K20 Center. (n.d.). Gallery walk/carousel. Strategies. https://learn.k20center.ou.edu/strategy/118
K20 Center. (n.d.). Tell me everything. Strategies. https://learn.k20center.ou.edu/strategy/107
K20 Center. (n.d.). Strike out. Strategies. https://learn.k20center.ou.edu/strategy/136
K20 Center. (n.d.). Looks like, sounds like, feels like. Strategies. https://learn.k20center.ou.edu/strategy/88
YouTube. (2021). Scientific Illustration I: A guided tour. YouTube. Retrieved January 30, 2023, from https://www.youtube.com/watch?v=6hmbGg9rMWQ
YouTube. (2022). Scientific Illustration Ii: Tips from an Insider. YouTube. Retrieved January 30, 2023, from https://www.youtube.com/watch?v=KvOXC2_5UCo