Define osmosis. Give a few examples where osmosis is helpful.

(N/A) Osmosis is the spontaneous net movement of water molecules from a region of higher water potential to a region of lower water potential through a selectively permeable membrane,such as the plasma membrane. This is a passive process,meaning it does not require the expenditure of cellular energy.
Examples where osmosis is helpful:
$(i)$ Freshwater organisms like $Amoeba$ and $Paramecium$ maintain their internal water balance through osmosis.
$(ii)$ The movement of water into and out of plant cells occurs primarily due to osmosis.
$(iii)$ Absorption of water from the soil by root hairs is facilitated by osmosis.
$(iv)$ It plays a crucial role in the opening and closing of stomata by regulating the turgor pressure of guard cells.
$(v)$ It is responsible for the seismonastic movements (thigmonasty) in the 'touch-me-not' plant ($Mimosa$ $pudica$).
$(vi)$ This process helps plant cells,tissues,and soft organs like leaves,young shoots,and flowers maintain turgidity and structural integrity.