The diagram given below is a representation of K⁺ transport mechanism of stomatal opening and closing. Study the same and answer the questions that follows:

(a) Name the cell labelled as A.

(b) Mention the states of guard cells represented by B and C.

(c) What causes closure of stomata during night?

(a) A represents epidermal cells.

(b) The state of guard cell represented by B is turgid and the state of guard cell represented by C is flaccid.

(c) During day, the guard cells have high concentration of K⁺ making it hypertonic. During night, the K⁺ ions are transported to epidermal cells due to which there is loss of water from guard cells making them flaccid. The stomata closes when guard cells are flaccid.