Venus flytrap virtual lab · 10 minutes
What happens when a trap closes without food?
Two traps on one plant snap shut at the same moment. Trap 1 closes empty. Trap 2 catches a housefly. Watch them at two points in time and use what you see to explain whether a snap always starts digestion.
Make a prediction
When the empty trap opens again, what do you think will be happening inside the fed trap? Why?
Compare the traps
- The experiment starts paused, six model hours after closure. In Digestion lens, switch between Trap 1 · Empty and Trap 2 · Fed. Record the state of each trap and what you see inside.
- Choose See when the empty trap reopens. Read the new model time. Switch between the traps again and complete the second row.
Opens in a new tab so you can keep this worksheet beside it.
Open the experiment at venusflytrapsim.com/?lesson=comparison
Record your observations
Type in the boxes or print a blank copy. Your notes stay in this tab. Use Print or Save as PDF before closing or reloading it.
| Model time | Trap 1 · Empty | Trap 2 · Fed |
|---|---|---|
| 6 hours | ||
| At reopeninghours |
Explain the evidence
Did both traps begin digesting? Support your answer with one observation from each trap. How does the evidence compare with your prediction?
Teaching notes and expected observations
Ask students to distinguish something visible, such as fluid around the fly, from an inference, such as the release of digestive enzymes. Both traps share a plant and a clock. The difference in this example is whether they caught moving prey.
At six model hours the empty trap is closed and contains no fluid. The fed trap is sealed around the fly with digestive fluid inside. At 16 model hours the empty trap has reopened while the fed trap is still digesting. These are checkpoints in this model. Timing varies in living plants.
In a real trap, signals from continued prey movement stimulate glands to release enzymes and absorb nutrients. The cutaway and amber fluid make those events visible in the simulator. Read Böhm and colleagues’ experiment on prey signals and digestion.