Stomata open in the night at alkaline or neutral $pH$ (in the atmosphere of ammonia vapours). This statement was given by

Identify the purposes of transpiration.
$I -$ Transpiration creates a transpiration pull for absorption and transport in plants.
$II -$ It supplies water for photosynthesis.
$III -$ It transports minerals from the soil to all parts of the plant.
$IV -$ It cools leaf surfaces by $10-15^{\circ} C$ through evaporation.
$V -$ It maintains the shape and structure of plants by keeping cells turgid.

Which of the following exhibits a direct proportionality to transpiration?

In barley type of plants,the stomata open:

Which of the following is the theory of stomatal opening and closing given by Lewitt?

Water lost by guttation is