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

What causes the opening and closing of guard cells of stomata during transpiration?

Rate of transpiration is increased by

Arrange the events of opening stomata in correct sequence and choose the correct option accordingly.
$I.$ Lowering of osmotic potential of guard cells
$II.$ Decline in guard cell solute
$III.$ Rise of potassium ion level in guard cells
$IV.$ Guard cells absorb water from neighbouring epidermal cells
$V.$ Guard cells become flaccid
$VI.$ Guard cells swell and create a pore between them

Guttation occurs in

Stomata when open lead to: