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2020 7-LS2-3

Page history last edited by Heather Johnston 1 year, 5 months ago

The Oklahoma Academic Standards for Science (OAS-S) are three-dimensional performance expectations representing the things students should know, understand, and be able to do to be proficient in science and engineering. Performance expectations are considered standards and include a science and engineering practice (indicated in blue and represent everyday skills of scientists and engineers), disciplinary core ideas (represented in orange and represent science ideas used by scientists and engineers), and a crosscutting concept (indicated in green and represent ways of thinking like scientists and engineers).


Each dimension in the OAS-S grows in complexity and sophistication across the grades. To learn more about the prior knowledge and skills students have developed (or future knowledge/skills) associated with that specific dimension, each section in the standard below is hyperlinked to that specific vertical learning progression page


7th Grade (7) Ecosystems: Interactions, Energy, and Dynamics

7.LS2.3 Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.

Clarification Statement: Emphasis is on describing the conservation of matter and flow of energy into and out of various ecosystems, and on defining the boundaries of the system.

Assessment Boundary: Assessment does not include the use of chemical reactions to describe the processes.

Science and Engineering Practices

Disciplinary Core Ideas 

Crosscutting Concepts

Developing and Using Models

  • Develop a model to describe phenomena.

Cycle of Matter and Energy Transfer in Ecosystems

  • Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem.

  • Transfers of matter into and out of the physical environment occur at every level.

  • Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments.

  • The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.

Energy and Matter

  • The transfer of energy can be tracked as energy flows through a natural system.

Connections to other Performance Expectations in Grade 7

Cycling of Energy and Matter



Navigation Links

Grade 7 Homepage

Grade 7 Science Standards and Bundle Analyses

3D Science Vertical Learning Progressions

OKScience Frameworks Introduction


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