Assertion (A): Transpiration is a biological activity
Reason (R): Transpiration occurs through living tissues of aerial parts of plants
Both A & R are true and R explains A
Transpiration is the process of water movement through a plant and its evaporation from aerial parts. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining water is lost by transpiration. Transpiration occurs chiefly in the leaves when the stomata are open for the passage of CO2 and O2 during photosynthesis.