Leaves having an equal number of stomata on both surfaces are called ........

What causes the opening of stomata in plants?

In barley type of plants,the stomata open:

The opening and closing of stomata takes place as a result of active transport of . . . . . . ions in guard cells.

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.

The transpiration in plants will be lowest when: