I plan to focus on MS-LS2-3 Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.
The Science and Engineering Practice is Developing and Using Models. I so appreciated the Bozeman Science videos on this student practice of making and using models to explain phenomena and analyze systems. I did not realize how important it was for students at a young age to start developing and using models. Hopefully, my 7th/8th grade students can draw from earlier experiences of making models of science phenomena. Even if they've had studied simple diagrams, they can now refine those models and add to them. I envision my students making a drawing of how an ecosystem of a pond works. While they may have learned a simple version of this in their younger years, they will now add environmental and abiotic or nonliving factors to their ecosystem drawing.
The Disciplinary Core Idea is the Cycle of Matter and Energy Transfer in Ecosystems. As the students will have learned about photosynthesis and cellular respiration earlier in the year, they can use these concepts in their model of pond life. They can show how matter and energy is transferred between producers, consumers, and decomposers interacting in an ecosystem. They can demonstrate how this cycle repeats moving between the living and nonliving parts of the system.
The Crosscutting Concept is that the transfer of energy can be tracked as energy flows through a system. They can demonstrate their knowledge of photosynthesis and cellular respiration on their drawing (model).