Interactive Labs › Biology labs
BBiologyS2 to S6Plant transport
Transpiration lab: a bubble potometer
A big tree can lose hundreds of litres of water on a hot day. Use a potometer to find what makes leaves lose water faster.
LevelS2 to S6 (and IGCSE, A Level)
TimeAbout 40 min
You useπ r² d, rates, percentages
PriceFree: no account
🎯 Aim
To investigate how light, air movement, humidity and temperature affect the rate of transpiration using a bubble potometer.
You will learn to
- Calculate the volume of water taken up from the bubble distance.
- Calculate rates and percentage changes.
- Explain each factor using stomata and diffusion gradients.
- State the limitations of a potometer.
🧭 What to do
- Start with Bright light, Still air, Dry room, 25 °C.
- Tap Time 5 minutes and read the distance moved by the bubble.
- Change one condition only, then time 5 minutes again.
- Compare the rates on the bar graph.
- Answer the questions with the class data.
- Write your conclusion and download your lab report.
📋 The data
Distance moved by the bubble in 5 minutes (capillary radius 0.5 mm) in five conditions.
🧠 Investigate: answer from the data
Type your answer and tap Check. Use 💡 Hint first; open the method only when you are stuck.
➕ Get more from this experiment
📝 Free
Print the worksheet (button above), download the data, and save your report. Teachers can project this page in class.
📦 Premium Lab Pack
1 000 RWF
- Practical worksheet for a home-made potometer
- Recording tables and rate calculations
- Teacher guide and answer key
- Exam-style plant transport questions with marking scheme
👩🏫 For teachers
Use it as a practical when apparatus is missing, as homework, or as a project. Free lesson plans help you plan, teach and assess.
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