2023 Transport in PlantsTranspiration – Transpiration Pull Medium Question 3 of 48 in Transport in Plants

Given below are two statements: Statement I: The forces generated by transpiration can lift a xylem-sized column of water over 130 meters height. Statement II: Transpiration cools leaf surfaces sometimes 10 to 15 degrees, by evaporative cooling. In the light of the above statements, choose the correct answer from the options given below:

A Statement I is incorrect but Statement II is correct.
B Both Statement I and Statement II are correct.
C Both Statement I and Statement II are incorrect.
D Statement I is correct but Statement II is incorrect.

The answer is B.

Solution

Transpiration pull can lift water over 130 m and evaporative cooling lowers leaf temperature.

A system of xylem vessels from the root to the leaf vein can supply the needed water. A pull force is created as water evaporates through stomata. These forces generated by transpiration can create pressure sufficient to lift a xylem-sized column of water over 130 metres high. Apart from creating transpiration pull for absorption and transport of plants it also helps in cooling leaf surfaces, sometimes 10 to 15 degrees by evaporative cooling.

Concept transpiration pull and evaporative cooling

Transport in Plants in past papers

48 questions from this chapter have appeared across 22 exam years.