Question

Which phenomenon is responsible to make the water rise up to $100 \,mts$ of tall plants ?

• A. Gravitation
• B. Transportation
• C. Transpiration pull
• D. Capillary action

Answer 1

Answer: (C)

Transpiration pull

Answer 2

On account of tension created by transpiration in the tracheary elements, the water column of the plant is pulled up passively from below to the top of the plant like a rope. As a tension of one atmosphere is sufficient to pull water to a height of about $10$ metres, a tension of $10-20$ atm is sufficient to raise water to the height of the tallest tree.