Today is rung 3 of 5 on this topic
Cells, organs and body systems
Can do: Explains how cells build tissues, organs and systems, and how two systems work together.
Why it matters
Levels of organisation is the mental model all of biology hangs on, and it's the first time scale itself has to be reasoned about.
What it looks like when it's wobbly
Knows the organs but not the levels, and treats each system as independent.
⏱️ Two-minute check
"Put these in order: organ, cell, tissue, system. How do the lungs and the blood work together?"
Solid looks like: The correct order and one clear link between two systems.
The full activity for this topic · 25 minutes
Follow the Oxygen
- 1Draw the journey of one oxygen molecule from air to a muscle cell and back as CO2.
- 2Label which system handles each stage.
- 3Measure resting pulse, then run up and down stairs and measure again.
- 4Explain the increase in terms of the whole chain of systems.
- 5Predict what happens to breathing rate too, then test it.
If it's too hard
Draw and label just the respiratory system.
If it's too easy
Add the nervous system's role in regulating the rate, and explain the feedback loop.
Say this
"Why did your heart rate go up? Trace it all the way back to what the muscle cells needed."