Previous-year question practice database
Answer
Exam answer
Hydathodes are located at the TIPS and MARGINS OF THE LEAVES, at the endings of the veins.
Explanation
Hydathodes are permanently open pores through which GUTTATION occurs — the loss of water in LIQUID form, as drops, rather than as vapour.
It happens at night or in the early morning, when the air is humid and the stomata are closed so transpiration cannot occur, but root pressure continues to push water up. The water is forced out through the hydathodes as visible droplets along the leaf edge.
THE DISTINCTION worth stating: guttation gives WATER DROPS from HYDATHODES; transpiration gives WATER VAPOUR from STOMATA. The drops on grass in the early morning may be either guttation or dew — dew condenses from the air, guttation comes from inside the plant.
More from Transpiration
Assertion (A): A thick cuticle reduces transpiration by acting as a barrier.
Reason (R): Desert plants have large, thin leaves for transpiration.2026Which plant phenomenon resulted in the wilting of the leaves?2026Mention the factor of the phenomenon that is being tested.2026A waxy layer on the upper epidermis of leaves meant to reduce Transpiration.2025Regulation of the opening and closing of stomata.2025Given below is a picture of a tree. Mention the scientific phenomena occurring in the parts labelled (a), (b) and (c).2025