HS-LS2-3
Construct and revise an explanation based on evidence for the cycling of matter and flow of energy in ecosystems.
Clarification statement: Emphasis is on conceptual understanding of the role of aerobic and anaerobic respiration and photosynthesis within ecosystems.
Assessment boundary: Assessment does not include the specific chemical processes of aerobic respiration, anaerobic respiration, and photosynthesis.
Resources
Examples and discussion of resources for the learning, teaching, and assessment of HS-LS2-3.

Assessment
What assessment of HS-LS2-3 might look like on a NY state exam.

NGSS Dimensions
Performance expectation HS-LS2-3 was developed using the following elements from the NRC document A Framework for K-12 Science Education:
- Constructing Explanations and Designing Solutions
- Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students' own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.
- LS2.B: Cycles of Matter and Energy Transfer in Ecosystems
- Photosynthesis and cellular respiration (including anaerobic processes) provide most of the energy for life processes.
- Energy and Matter
- Energy drives the circulation of matter within and between systems.