Starter quiz
- What do plants need to perform photosynthesis?
- carbon dioxide, oxygen, and water
- oxygen, light, and glucose
- water, light, and carbon dioxide ✓
- water, oxygen, and sunlight
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- Which part of the plant is primarily responsible for water absorption?
- flowers
- leaves
- roots ✓
- stems
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- What is the function of stomata in leaves?
- gas exchange and water loss ✓
- nutrient absorption
- photosynthesis
- water uptake
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- What is transpiration?
- the absorption of nutrients by roots
- the exchange of gases in leaves
- the process of photosynthesis
- the process of water loss from the leaves ✓
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- What is the transportation stream?
- the flow of water in a river
- the evaporation of water from the leaf of a plant
- the movement of water and dissolved minerals through a plant ✓
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- How do you calculate the rate of a process?
- change ÷ time taken ✓
- change × time taken
- time taken ÷ change
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Exit quiz
- What does a potometer measure?
- the rate of gas exchange
- the rate of photosynthesis
- the rate of transpiration
- the rate of water uptake by a plant ✓
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- How does light intensity affect the rate of water uptake in plants?
- Higher light intensity decreases the rate of water uptake.
- Higher light intensity increases the rate of water uptake. ✓
- Light intensity has no effect on water uptake.
- Lower light intensity increases the rate of water uptake.
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- What is the formula to calculate the rate of water uptake?
- change in volume of water ÷ time taken ✓
- change in volume of water × time taken
- volume taken ÷ time change
- time taken ÷ change in volume of water
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Why is a beaker of water used in this experiment?- to control temperature ✓
- to increase light intensity
- to measure light intensity
- to protect the plant from water loss
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- What are the roles of stomata in leaves?
- gas exchange ✓
- nutrient absorption
- photosynthesis
- to control water loss ✓
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- During a potometer experiment lasting 20 minutes, the start reading was 0.5 cm³ and the end reading was 3.2 cm³. What is the rate of water uptake?
- 0.135 cm³/min ✓
- 0.105 cm³/min
- 0.145 cm³/min
- 0.120 cm³/min
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Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- Practical demonstration of the use of a simple potometer to measure water uptake by a leafy shoot.
- Use of a light source to vary light intensity.
- Use of appropriate apparatus to control temperature (e.g. a water tank as a heat shield between light and plant).
- Use of a simple potometer to measure water uptake by a plant at a range of light intensities.
- Rate of water uptake = change in volume of water ÷ time taken for volume to change
Common misconception
Being able to explain the set up of a potometer is difficult because it has so many stages that are tricky.
The stages of setting up a potometer are broken down into four parts, checked for understanding, reinforced with a lab demonstration video and concluded with a cartoon task.
Keywords
Transpiration - the loss of water from a plant’s leaves
Potometer - a piece of equipment used to measure the rate of water uptake by a plant
Control - a variable which is kept constant between all experiments
Light intensity - the amount of light reaching a given area in a given time
Rate - a measure of how much change occurs per unit of time
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