Most of the transpiration from plant parts takes place through minute openings called stomata. 

Maximum transpiration takes place from the surface of leaves as they possess maximum number of stomata. 

Rate of transpiration will be maximum, if the stomatal pores are open, atmosphere is dry and soil is moist.

The rate of transpiration during storms is nil. Because the surrounding atmosphere already possesses large amount of water during a stormy and cloudy day.

Exchange of gas (CO₂) and water is regulated by the opening and closing of stomata.

Transpiration can be defined as the process of loss of water from the surface of exposed aerial parts of water. It helps to translocate water and minerals and also provides cooling effect to plants during summers. 

The widening of stomatal pores is due to the presence of water content in excess in a plant.

Water lost in transpiration is pure water. It does not contain any solute particles (minerals and salts). 

Transpiration is partly physical and partly physiological process. 

Maximum transpiration takes place from the lower surface of the leaves. If this portion is greased, the loss of water taking place from the plant will be very less.

In submerged plants, stomata are present but they are not functional. Hence, they do not play any role in transpiration. 

The rate of transpiration decreases with increase in humidity. Higher the humidity in the atmosphere, the lower will be the rate of transpiration. 

Blue light is most effective for stomatal opening. 

Maximum stomata are present on the lower part of a leave so as to minimize the loss of water during transpiration. 

In transpiration, diffusion of water molecules takes place out of the plant cells.