Trace nutrient and oxygen delivery
Trace nutrient and oxygen delivery using supplied evidence and a solved model.
About 25 minutes, plus any extended practice
Supplied materials
- All measurements and observations below are supplied classroom examples. They are not data from actual learners or a claim about a particular real site.
- Paper or a browser document for a labeled drawing, table or explanation.
- Worked problem inputs: A model has nutrients absorbed but oxygen delivery blocked. Explain why successful digestion alone does not complete the pathway.
- Assessment case 1: A nutrient enters intestinal blood but circulation to tissues stops in the model. What is predicted? Which inference or prediction is best supported?
- Assessment case 2: Which scientific label fits the specifically described step or feature? Supplied case: Oxygen enters blood at lung surface.
- Assessment case 3: Which scientific label fits the specifically described step or feature? Supplied case: Blood delivers glucose to tissues.
- Assessment case 4: Which scientific label fits the specifically described step or feature? Supplied case: Cells transfer energy from nutrient reactions.
- Assessment case 5: Which scientific label fits the specifically described step or feature? Supplied case: Food molecules are broken down.
- Assessment case 6: Carbon dioxide moves from tissue blood to lung air in the model. Why is circulation relevant? Which inference or prediction is best supported?
Learn the idea
Digestion supplies absorbed nutrients, breathing exchanges gases and circulation transports materials. Cells use chemical reactions to transfer energy. This general model is not a health diagnosis.
Digestion means breakdown and absorption of food materials. Gas exchange means oxygen and carbon dioxide exchanged. Transport means blood carries materials to tissues. Cellular use means cells use materials in chemical processes.
For the supplied mechanism problem, A model has nutrients absorbed but oxygen delivery blocked. Explain why successful digestion alone does not complete the pathway. Digestion supplies nutrients, but aerobic processes also need oxygen delivery. Respiratory and circulatory functions interact with digestion; one functioning system does not substitute for the others.
- Read the supplied problem and mark the structures, processes or quantities named: A model has nutrients absorbed but oxygen delivery blocked. Explain why successful digestion alone does not complete the pathway.
- Draw the relevant boundary, pathway or comparison and label it using the scientific ideas above.
- Write a causal explanation or calculation, showing how each observation supports the result.
- Compare your reasoning with the worked solution; name a condition that would change or limit the inference.
See the method in action
Worked supplied problem: A model has nutrients absorbed but oxygen delivery blocked. Explain why successful digestion alone does not complete the pathway. Solution: Digestion supplies nutrients, but aerobic processes also need oxygen delivery. Respiratory and circulatory functions interact with digestion; one functioning system does not substitute for the others. This conclusion uses the stated observations and the mechanism explained above; it does not establish every unmeasured feature of a real organism, device or place.
Check your reasoning
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Helpful tips
- Use the feature “breakdown and absorption of food materials” to justify digestion; do not sort by the name alone.
- Distinguish gas exchange (oxygen and carbon dioxide exchanged) from a different process occurring in the same situation.
See the answer and explanation
Absorption alone does not deliver that nutrient to distant cells.
Absorption and circulatory transport are cooperating steps with different functions.
Take it further
New task: draw a nutrient route from intestine to blood to cells, and an oxygen route from lungs to blood to cells. Expected: digestive and respiratory inputs converge through transport; neither alone describes the complete aerobic pathway.
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More practice: try new cases
Choose an answer for each problem. Explain your method on paper, then use the feedback to decide what to revisit.
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Check the subject sources
These LifeStarter passages, scenarios and exercises are authored for this Academy with AI assistance and review. External resources keep their publishers’ terms. A grade label suggests a starting level; it does not establish alignment with your school’s complete requirements.