Question 2
FA student used a potometer to measure the rate of water uptake by a leafy shoot.
The Figure shows the apparatus.
Figure
The student measured the distance the air bubble moved in 10 minutes under three different conditions.
The Table shows the results.
Table
| Condition | Distance moved by air bubble in 10 minutes in mm\text{mm}mm |
|---|---|
| still air at 20 ∘C20\ ^{\circ}\text{C}20 ∘C | 15 |
| moving air from a fan at 20 ∘C20\ ^{\circ}\text{C}20 ∘C | 42 |
| still air at 30 ∘C30\ ^{\circ}\text{C}30 ∘C | 28 |
a.[2]
The student cut the shoot under water before putting it into the potometer.
Explain why.
b.[1]
Calculate the rate of movement of the air bubble in moving air from a fan, in mm\text{mm}mm per minute.
c.[3]
Explain why the air bubble moved further in moving air than in still air.
d.[2]
Explain why the air bubble moved further in still air at 30 ∘C30\ ^{\circ}\text{C}30 ∘C than in still air at 20 ∘C20\ ^{\circ}\text{C}20 ∘C.
e.[1]
A potometer measures the rate of water uptake, not the rate of water loss.
Give one reason why these two rates are not the same.
6.2 Transport in plants Questions
43 exam-style questions on Edexcel GCSE Biology 6.2 Transport in plants, covering 6.2.1 Root hair cell adaptations, 6.2.2 Structure of xylem and phloem, 6.2.3 Transpiration and stomata, 6.2.4 Translocation of sucrose, 6.2.5 Leaf structure for photosynthesis, 6.2.6 Environmental factors on water uptake, 6.2.7 Rate calculations for transpiration, and 6.2.8 Plant adaptations to extreme environments. Each one has a worked solution and a mark scheme showing where the marks go.