Question

Which among the following objectives regarding transpiration are achieved by Ganong's potometre?

• A. It measures the rate of water intake by a plant.
• B. Demonstrates the suction force created by transpiration.
• C. Demonstrates unequal transpiration from the two surfaces of a dorsiventral leaf.
• D. Demonstrates unequal transpiration from the two surfaces of an isobilateral leaf.

Answer 1

The correct option is A It measures the rate of water intake by a plant.

$\bullet$ Ganong's potometre helps to measure the rate of transpiration in plants. The ganong's potometre set-up does not directly measure the rate of water loss but measures the rate of water absorbtion (intake) by a plant. The design of the set-up is done in a certain way such that the rate of water absorption is proportional to the rate of water loss. In this way, the transpiration rate is measured.

$\bullet$ Other potometres like Darwin's potometre helps to demonstrate the suction force created due to transpiration and Garreau's potometre demonstrates the unequal transpiration from the two surfaces of a dorsivental leaf.