Target: use the cell→tissue→organ→system hierarchy as a contribution chain, not a claim that one tissue alone builds the organ. Prepare: Card E and hierarchy staircase.
- Launch · 2 min. Ask whether a single intestinal epithelial cell is the small intestine; keep a yes/no reason.
- Model · 4 min. Read
intestinal epithelial cell → epithelial tissue → small intestine → digestive system. Each arrow means contributes to the next level; the organ contains other tissues. - Guided reading · 5 min. Build the independent cardiac chain from Card E and ask what the heart contributes to the circulatory system. Do not turn either chain into an illness lesson.
- Practice route · 7 min. Choose Day 8 route; arrange both chains and justify one arrow with the word “contributes.”
- Audit · 4 min. Peer inserts “only” into “epithelial tissue makes the intestine”; learner removes it and explains why.
- Exit · 3 min. “What level is the small intestine in this chain?” Key: organ, with multiple tissues.