State any two adaptations in plants to reduce transpiration.
Topic: Adaptations to reduce transpiration
Answer
- SUNKEN STOMATA — the stomata lie in pits below the leaf surface, where moist air is trapped, so the rate of evaporation is reduced.
- A THICK WAXY CUTICLE on the leaf surface, which is impermeable to water and so cuts cuticular transpiration.
(Also acceptable: reduced leaves or spines, as in cactus; fewer stomata; a hairy leaf surface that traps moist air; leaf fall in the dry season.)
Two adaptations, one mark each, and for each state the FEATURE and WHY it works — the question is about reducing transpiration, so the mechanism is part of the answer.
THE PRINCIPLE behind almost all of them: evaporation slows when the air immediately outside the stoma is ALREADY MOIST. Sunken pits and surface hairs both work by trapping a layer of humid air against the leaf.
These are XEROPHYTIC adaptations, found in plants of dry habitats. Note the contrast with the 2026 paper’s assertion-reason question, which wrongly claimed desert plants have "large thin leaves" — they have exactly the opposite, small and thick, for this reason.