Question

With an increase in temperature, the rate of transpiration becomes
A) Low
B) High
C) Low in herbs and high in trees
D) Immediately stops

Answer 1

Hint:-Transpiration is the process of movement of water through a plant and evaporation of water from the aerial parts such as leaves, stems, and flowers. Up to 97–99.5 percent of water content is lost by transpiration and guttation. Transpiration is caused by the evaporation of water at the interface of the leaf and atmosphere which creates a negative pressure or water potential gradient at the surface of the mesophyll cells that cause water to move upwards from the roots via xylem.

Complete Answer:-
Transpiration helps in the cooling of plants and maintains the temperature of the plant, changes the osmotic pressure of cells, and enables mass flow of mineral nutrients and water from roots to shoots, and also regulates the turgor pressure. The rate of transpiration is determined by various factors which include temperature, sunlight, wind, and humidity. It occurs chiefly in leaves while their stomata are open for the passage of Carbon dioxide and Oxygen during photosynthesis. Plants transpire more rapidly at higher temperatures as the water evaporates more rapidly at higher temperatures. A leaf transpires about thrice as fast as it does at a temperature of 10 degree Celcius more than before. Transpiration occurs mainly during the opening of stomata for the exchange of carbon dioxide and oxygen for photosynthesis. The plants can regulate the rate of transpiration by controlling stomatal aperture size.
Thus, the right option is B.

Note:- Morphological features like the evaporative demand of the atmosphere surrounding the leaf also contributes to the rate of transpiration. An example includes the boundary layer conductance. Due to this reason, the rate of transpiration in plants is higher as they need to open the stomata to take in carbon dioxide for photosynthesis at lower concentrations.