Question

Opening and closing of stomata during day and night is an example of?

Answer 1

Stomata are small pores in the epidermis of leaves, stems, and other plant organs. Gases such as carbon dioxide, water vapor, and oxygen can pass into and out of the plant's intrinsic tissues through stomata. Guard cells are a type of specialized parenchyma cell that surrounds the pore and controls the extent of the stomatal opening.

Complete answer
Stomata open and close in reaction to the turgor of guard cells. The pore is enclosed by a strong and ductile cell wall. The structure of guard cells varies between monocots and dicots, but the function is the same in both. Guard cells have chloroplasts which have chlorophyll and can absorb light.
In most plants, stomata open during the day and shut at night. Because these movements are linked to diurnal shifts in day and night, they are referred to as sleeping or seis monastic movements.
Stomata open and close as the turgidity of the kidney-shaped guard cells surrounding the stomatal aperture varies. Guard cells grow turgid during the day, and stomata open. Guard cells become flabby at night, and the stomata seal. Because the opening and closing of stomata is caused by variations in the turgidity of guard cells, these movements are sometimes referred to as turgor movements.

Note:
The turgor pressure, which is created by the osmotic movement of water in the guard cells, controls the opening and closing of stomata. The guard cells widen when they become turgid, enabling the stomata to reopen. Guard cells become floppy when they lose water, causing stomatal closure. Stomata generally open when the leaf is exposed to light and close at night.