NGSS HS-LS2-4
The Standard
Use a mathematical representation to support claims for the cycling of matter and flow of energy among organisms in an ecosystem.
Next Generation Science Standards
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students build or interpret a numerical model showing energy stored in biomass at several trophic levels. They use proportional reasoning to support claims about energy transfer and the conservation of carbon, oxygen, hydrogen, and nitrogen.
What Mastery Looks Like
- Students calculate energy or biomass transfers using ratios, percentages, tables, or pyramids. They use the model to explain energy loss between trophic levels and the continued movement of atoms through organisms and the environment.
Common Misconceptions
- Students may say energy cycles like matter. They may treat biomass as population count rather than stored organic matter. They may assume all stored energy transfers to the next trophic level.
How to Assess It
- Give students this exit ticket: Grass stores 20,000 kJ, grasshoppers store 2,000 kJ, and frogs store 200 kJ. Calculate each transfer percentage, then explain what flows and what cycles.
Lesson moves
Ways to Teach It
Use two colors of counters to model energy transfer and carbon movement through producers, consumers, decomposers, and the environment.
Write a claim explaining why hawks have less stored biomass than grass, using a labeled energy pyramid as evidence.
Run a calculation relay where teams complete missing biomass values on food chain cards using given transfer percentages.
Analyze biomass data from a local lake or farm, then predict how changes in producers would affect higher trophic levels.
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Printable HS-LS2-4 Worksheet
A ready-to-print activity worksheet aligned to HS-LS2-4, with an answer key for the teacher on its own page. No account needed.
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Related Standards
- MS-ESS2-1
Develop a model to describe the cycling of Earth's materials and the flow of energy that drives this process.
- HS-LS2-3
Construct and revise an explanation based on evidence for the cycling of matter and flow of energy in aerobic and anaerobic conditions.
- MS-LS1-6
Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms.
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