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Tom,
It's great to have pushback from teachers who want to challenge students and that you are passionate about getting the science right. I’m wholeheartedly on the same team, but I think what we’ve bumped into here is not about the science being “wrong,” but rather grade level appropriate descriptions of the science. Here are a couple of points of clarification:
The standards represent what all students should know and be able to do by a particular grade level across all science domains. There are many things that we think that kids should know or are capable of knowing, but to ensure that students are prepared for their lives beyond high school, there are trade-offs about the level of detail that it is possible to delve into with each core idea. In this particular case, the details of the Krebs cycle and the electron transport chain (though as a bio guy, I personally find them fascinating and would love for all students to understand them the way I do) don’t rise to this level. They don’t need to be ignored and certainly shouldn’t be misrepresented, but ensuring that all students learn the details of these cycles is not expected.
Though I can certainly see how one might interpret the text this way, the standards do not intend to claim that oxygen and sugars react directly with each other. This phrase is used in this case to represent the fact that the standards are intentionally not going to the detailed level that you discussed. So, at this point, we really are talking about the summary equations for both photosynthesis and respiration and not the details of the process. I’m sure that you already do this as is indicated by your use of Framework language in your post, but when I bump into issues like this, I check out Appendix E: Disciplinary Core Idea Progressions that lays out how each core idea builds over time in the NGSS using the key ideas from the Framework, NSTA’s DCI Matrix that links together the elements of the standards and/or the Framework itself by clicking on the links embedded in the standards to verify what is really intended.
For example, for PS3.D which is mentioned twice above, here’s the full text from this section of the Framework :
By the end of grade 8. The chemical reaction by which plants produce complex food molecules (sugars) requires an energy input (i.e., from sunlight) to occur. In this reaction, carbon dioxide and water combine to form carbon-based organic molecules and release oxygen. (Boundary: Further details of the photosynthesis process are not taught at this grade level.)
Both the burning of fuel and cellular digestion in plants and animals involve chemical reactions with oxygen that release stored energy. In these processes, complex molecules containing carbon react with oxygen to produce carbon dioxide and other materials.
Machines can be made more efficient, that is, require less fuel input to perform a given task, by reducing friction between their moving parts and through aerodynamic design. Friction increases energy transfer to the surrounding environment by heating the affected materials.
In NSTA’s matrix of the elements used in the standards for PS3.D, you can see the following progression:
As you can see across both of these sources, the focus of the core idea for PS3.D is on energy within these reactions and not the details of the reaction. In fact, you can also see a clear boundary provided by the Framework document that the details of photosynthesis are not what students are held accountable for at this grade level.
A similar process for LS1.C shows that the focus for photosynthesis from the 8th grade endpoint from the Framework is on the fact that “Plants, algae (including phytoplankton), and many microorganisms use the energy from light to make sugars (food) from carbon dioxide from the atmosphere and water through the process of photosynthesis, which also releases oxygen. These sugars can be used immediately or stored for growth or later use.” And for respiration, the focus is on the idea that, “…food moves through a series of chemical reactions in which it is broken down and rearranged to form new molecule
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