IB Biology HL 3.2.7 Water Transport in Plants Question Bank
Practise IB Biology HL 3.2.7 by linking water properties, xylem structure, cohesion and transpiration pull from roots to leaves.
- Syllabus
- First assessment 2025
- Course
- Biology HL
- Level
- HL
Practise IB Biology HL 3.2.7 by linking water properties, xylem structure, cohesion and transpiration pull from roots to leaves.
The rate of transpiration can be measured using a data-logging pressure sensor connected to a plant cutting via a plastic tube. In an experiment, a control set-up was connected to the tube and placed in a well-lit room with normal humidity levels.

Predict, with a reason, what will happen to the pressure in this tube as transpiration occurs.
a. pressure will decrease
b. water volume decreases «in tube» due to evaporation transpiration
c. «cohesion/tension of water column» causes increase in air volume «thus air pressure decreases»
OWTTE
2 max