The representation depicts the transfer of energy in a food chain. The resource is an interactive illustration of a farm scene depicting the flow of energy between the sun, a cornfield, a cow and a human through a food chain. To view the illustration, select Continue, then select Energy Flow button.
- Resource Copyright Owner: WGBH Educational Foundation
- Type of Resource: application/x-shockwave-flash
The resource addresses the actual substance of the learning goal rather than
just the topic.
The five numerical selections in the representation describe energy at each stage in the food chain and how much energy is transferred between organisms.
The resource addresses the indicated part of the learning goal:
Matter and [energy [is] transferred repeatedly between organisms] and between organisms and their physical environment.
The resource correctly reflects the level of sophistication of the learning
The food chain is simple and vocabulary terms are appropriate. The discussion of energy transfer uses the mathematical concept of percents. At each stage, the resource both describes how energy can be transferred to the next stage and also accounts for the remaining energy used to maintain life or lost as heat energy.
Notes for Teachers
This learning goal is reinforced through the latter half of the set of interactive questions and the final diagram demonstrating all of the energy transfers in the depicted system. The final diagram emphasizes that the energy in the final hamburger came from the sun; teachers would be advised to also emphasize that the energy the human derives from the hamburger is the same energy originally stored in the corn.
Quality of instructional support
Does the representation accurately represent relevant aspects of the learning goal and/or brings out limitations that are not accurate?
Yes—The representation accurately represents relevant aspects of the learning goal and brings out inaccuracies, if there are any.
The resource discusses the transfer of energy at each step in the food chain. Both the source of energy and the use of energy are described for each organism. The resource emphasizes that a considerable amount of the energy at each step is emitted as heat or used for life-sustaining processes.
Is the representation likely to be comprehensible to students?
Partial—The representation might make the learning goal comprehensible to students.
Energy is not defined or represented visually in this resource (except for a ray of sunlight). The resource repeatedly describes how energy is "used." Some students may think "in terms of energy 'formed' or 'used' in biological processes rather than in terms of energy conversion" (Driver et al, p. 60). The depiction of the ray of sunlight pointing toward the hamburger in the final diagram may reinforce an incorrect belief that food energy is directly transferred to the hamburger from the sun.
Does the representation make clear which aspects of the real thing are represented and which are not?
Partial—The representation usually, but not always, makes clear which aspects of the real thing are represented and which are not.
The representation repeatedly describes the transfer of energy between organisms at each step in the food chain and discusses the loss of energy between organisms. The final representation depicts a curved sunbeam terminating at a hamburger. The text portions clarify the energy transfers, but the representation does not directly depict any of the individual energy transfers or the energy losses.
Useful with modification
Notes to teachers
Teachers may wish to emphasize that energy from the sunlight is not itself converted into matter in the organisms or foods depicted. The energy from light is used to produce sugars from carbon dioxide and water in the plant. Some of the energy is stored in the sugars, and when an organism eats the plant, some of the energy gets transformed to usable energy in that organism.
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