Read the below statements about transpiration:
- Transpiration is highest in dry and windy conditions.
- It helps in the ascent of sap through cohesion-tension.
- Transpiration always results in wilting.
Which of the above statements are correct?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. Only 1 and 2 are correct.
Statement 1 is correct: High wind and low humidity increase the vapor pressure gradient, accelerating water loss from leaves.
Statement 2 is correct: Transpiration creates a "pull" (suction) that, combined with the cohesion (water-water attraction) and tension of water molecules, lifts the ascent of sap from roots to canopy.
Statement 3 is incorrect: Transpiration only leads to wilting if the rate of water loss exceeds the rate of water absorption by the roots. Under normal conditions, it is a vital cooling and transport mechanism.