Majority of potometers measure the rate at which water is:

Water moves up against gravity and even for a tree of $20 \,m$ height, the tip receives water within two hours. The most important physiological phenomenon which is responsible for the upward movement of water is $...........$

The loss of water in the form of liquid occurs through . . . . . . .

The transpiration is regulated by the movements of

Observe the diagram and answer the following:
$(a)$ Identify the types of guard cells shown in $(i)$ and $(ii)$.
$(b)$ Which of these types is found in monocots and which in dicots?

The opening and closing of stomata due to the activity of water is known as: