Question

Water Transpiration is beneficial as well as harmful for photosynthesis. Justify

Answer 1

Transpiration is defined as the process which enables moisture to be carried through plants from roots to small pores on the underside of leaves, where it is converted to vapor and is released into the atmosphere. Plants face a dilemma when it comes to water conservation and expenditure. For plants to perform photosynthesis, they must keep their stomata open so that carbon dioxide can enter. But leaves must also retain a certain amount of water internally in order to maintain the turgor pressure and to provide water for photosynthesis. The result is that, on a sunny day when photosynthesis is at its peak, the plant is simultaneously losing a lot of water through the open stomata. If the plant closes its stomata in order to conserve water, the exchange of gases would stop, hence depleting carbon dioxide and stalling photosynthesis. ​Rates of transpiration and water loss depend on the temperature of the air, humidity, wind, and the surface area of the leaf. On a hot, dry, sunny day with a warm breeze, plants with large leaves lose a tremendous amount of water. On a cool, cloudy, humid day, plants transpire far less.