Choose a stop. Gather evidence.
Revisit any investigation while this tab is open.
Teacher controls
Start with a prediction. Open the teaching route when you want setup, prompts, recovery, and synthesis.
Nucleus selected.
A colour-coded teaching model of a typical cell. Shapes, colours and relative sizes are simplified; this is not a microscope image.
Comparison lens
One structure. Two cell models.
These are typical teaching models. A photosynthetic plant cell has chloroplasts; many root cells do not.
Explore the structure
Small parts. Shared work.
Choose a structure to see what it does. Then switch cells: which structures do both need?
The nucleus holds the cell's DNA and directs what the cell does. Plant and animal cells both have one.
Compare a typical animal cell with a photosynthetic plant cell. Real cells vary with their job.
From one cell to a system
A cardiac muscle cell is one specialized cell. Inspect it, then build a relationship to the next scale.
Simplified, not to scale: each inset preserves the earlier relationship; it does not show cells transforming into organs.
Diffusion
Dissolved particles spread from where they are crowded toward where they are less crowded. They can cross this membrane. At an even distribution, real particles keep moving both ways, with no net movement.
Left particles 12
Right particles 2
Sugar on the right 0
Blue paths: oxygen-poor blood. Gold paths: oxygen-rich blood. These are diagram colours; blood is always red.
A double loop
In body capillaries, oxygen leaves the blood for cells and carbon dioxide enters the blood.
Blood goes to the lungs and comes back to the heart before it goes out to the body. On this sketch the right side of the heart is on the left, because the heart faces you. Arteries leave the heart. The pulmonary arteries carry oxygen-poor blood, so an artery is not always oxygen-rich.
Learner evidence notebook
Build one explanation from structure and delivery evidence.
0 of 4 evidence notes collected.
Evidence-to-explanation worksheet
Claim: How does oxygen get from lungs to a body cell?
Cell evidence: ____________________
Route evidence: ____________________
Optional organization evidence: What relationship did you observe between the parts? ____________________
Because reasoning: ____________________
Limitation: ____________________
Evidence map
Model observation that helps support our explanation: ____________________
System context: ____________________
What this model cannot establish: ____________________
Transfer challenge
Use your cell and oxygen-route evidence to explain why a working muscle cell needs the circulation loop. Write 3–4 sentences.
Synthesis map
Which observations belong in your explanation?
Place an earned observation, then strengthen your existing evidence-and-reasoning sentence with because. You can revise your placements.
Model observation that helps support our explanation
System context
This model cannot establish
Teach this investigation Classroom route, discussion prompts & model limits
Teacher quick route
Keep the room moving.
Start with the prediction. Pause pairs when they can point to one observation.
- 1 minStudents commit a first idea.
- 4 minPairs make the model change.
- 2 minHear evidence, then revise.
If a pair stalls: ask “What changed in the model?” before naming a term.
Teach this investigation
One lesson route: predict, observe, connect, explain.
Purpose & setup
Learning target: use observations from models to connect cell structures, organization, exchange, and delivery.
Materials: one projected screen; pairs share one device or take turns. No login or extra equipment.
Sequence
Launch: “What must happen between a cell and the body for it to stay alive?” Students predict before opening a model.
Pairs: one operates, one records the visible change; swap each investigation.
Look-fors & recovery
Listen for: observations before conclusions. Correct “all arteries carry oxygen-rich blood” with the pulmonary-artery route.
If technology stalls: project the current diagram, have pairs trace or compare what is already visible, then record one observation aloud.
Synthesis & exit
After the structure and delivery notes appear, ask pairs: “Which model note helps, which gives context, and which limit must we say?” If a pair stalls, reread the model limits and revise one placement. Organization and exchange are optional supporting observations.
Start with a question
Ask: “A muscle cell needs energy to contract. What must reach it, and what must leave?” Have students sketch a first idea before exploring.
Follow one connected route
Compare cells → build the relationship from a cardiac muscle cell to tissue, heart, and circulation → observe movement across a membrane → trace oxygen from lungs to body cells. The scale model uses insets: cells do not grow into a heart. Work in pairs: one operates; the other explains the evidence. Swap roles each investigation.
Collect the explanation
Exit prompt: “Explain how the circulatory system helps a muscle cell do its job. Name a cell structure, a transport process and a site of exchange.” Listen for connections, not just names.
Make the model visible
Read the captions aloud and use the labelled buttons instead of relying on colour. Students can give an oral explanation or draw arrows. Diagrams are simplified and not to scale; the particle model shows direction, not a measured rate.
01 Cells
Start: predict a shared structure. Task: inspect both cells. Exit: name the shared evidence.
02 Organization
Start: predict a route. Task: build cell → tissue → heart → circulation, naming what each relation adds. Exit: distinguish respiratory lungs from the circulatory system.
03 Membrane
Start: predict osmosis. Task: observe three steps. Exit: state what moved and what stayed.
04 Oxygen
Start: predict the next stop. Task: trace the route. Exit: connect lungs, heart and body cells.