Invitation: “Show why a web needs more than feeding arrows.” Prepare: G1–G3; matter-energy aid. Selected opportunities: U02 / I04 / I06; conditional on actual component evidence, not blanket code completion.
Make one trace · 5 minutes
Learners choose to start with sunlight entering a producer or with dead organic material/mineral nutrients. Draw/describe one named step immediately. Use their earlier work only if genuinely available; the separate process aid is sufficient.
Read the process capsules · 8 minutes
Read G1–G3 in short parts. Explain that plants transform light energy into chemical energy in sugars, with carbon dioxide and water supplying matter. Soil mineral nutrients matter too; they do not supply sunlight. Define respiration as a process using chemical energy, not just visible breathing.
Create contrasting pathways · 12 minutes
Learners make an energy path Sun→producer→consumer with a branch to heat; then a selected mineral-nutrient matter loop soil nutrients→plant material→dead material/decomposition→soil nutrients. Name decomposition, not all fungi. The loop is a selected matter pathway, not the full ecosystem. One path now is enough. Pause at 25 minutes.
Add a carbon explanation · 15 minutes
Offer air carbon dioxide→plant sugars→consumer material and respiration/decomposition→air carbon dioxide as a different matter trace. Let learners compare it to the soil-mineral loop by pointing, words or drawing. Keep light on the energy trace, not as matter in the loop. Ask whether the energy arrow should return from soil to the Sun: no, the model needs ongoing energy input.
Resolve a useful claim · 6 minutes
Present only the ordinary claim: “Soil sends recycled sunlight back to plants.” Learners use a trace to explain or repair it. A useful repair is that soil can supply mineral nutrients while sunlight supplies energy. Require neither chemical equations nor all atom pathways. Do not teach a fixed ten-percent rule.
Keep an explanation · 4 minutes
Choose one caption or spoken sentence that helps the learner use their explainer. Record the actual distinction encountered and a next step, not a full matter/energy mastery claim.
Practical check: Sample one actual source-connected choice/reason in the chosen mode. Use Day 23 routes, two worked contexts and home/extra invitation only as useful.