This exam tips covers Exam Success Tips within Transpiration for GCSE Biology. Transpiration process, stomatal control, factors affecting rate, plant adaptations, measuring transpiration, and practical investigations It is section 11 of 21 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Exam Success Tips
- Remember THAW: Temperature, Humidity, Air movement, Water/light - factors affecting transpiration
- Potometer limitation: Always state it measures uptake, not transpiration directly
- Guard cell mechanism: K⁺ ions → osmosis → turgor → shape change
- Adaptations: Link structure to function (e.g., sunken stomata trap humid air)
- Graphs: Be ready to interpret transpiration rate vs time or environmental factors
- Calculations: Rate = distance/time, remember units (mm/min or ml/hour)
- Practical skills: Explain why cutting underwater prevents air bubbles
- Integration: Link to xylem structure (Topic 14) and gas exchange (Topic 13)
Practice questions for Transpiration
What is transpiration?
Describe the three stages of transpiration in a leaf.
Quick recall flashcards
What is a potometer?
An apparatus that measures the rate of water uptake by a plant shoot. Used to estimate transpiration rate (though actually measures uptake, not loss).
What is a xerophyte?
A plant adapted to survive in dry/arid conditions with limited water availability (e.g., cacti, marram grass).