Which part of the living system did you change?
Labs / Biology
Transpiration Stream
Water evaporates from the leaves and drags a continuous chain of water up the xylem, all the way from the roots. Drag the sun, tap the leaves to open or close the stomata, and change the weather — then watch how fast the stream flows and whether the plant can drink quickly enough to stay turgid.
Labs / Biology / Transpiration Stream
Transpiration Stream
Water evaporates from the leaves and drags a continuous chain of water up the xylem, all the way from the roots. Drag the sun, tap the leaves to open or close the stomata, and change the weather — then watch how fast the stream flows and whether the plant can drink quickly enough to stay turgid.
Why it matters
Why explore this?
Living systems are connected and constantly changing. This model makes one biological process visible so you can test how its parts affect one another.
Explore
Try the model
E 0Uptake 0VPD 0Leaf turgid
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- Close the stomata. Where does the water stream go, and what happens to the transpiration rate?
- Crank up the heat and drop the humidity. Why does the vapour-pressure deficit (VPD) climb, and how does the leaf respond?
- Add wind on a dry day. Why would a breeze pull water out of a leaf faster than still air?
- Push transpiration higher than the roots can supply. How long before the leaves start to wilt — and can you reverse it?
- Dim the light to nearly nothing. What do the guard cells do, and why might a plant close up when it is dark?
Explain
Make sense of what happened
Explain the process as a chain: a change happens, the system responds, and that response affects what happens next. Use an observation from the model as evidence.
Check
Before you leave
How did the system respond?
How would you explain that response?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.