Why does the following action take place in plants?
Plant cells change shape by changing the amount of water in them, resulting in swelling or shrinking, and therefore in changing shape.

Correct option is A

• When plant cells gain water, they swell (become turgid).

• When they lose water, they shrink (become flaccid).
  This change in pressure leads to movement of plant parts in response to stimuli such as touch, temperature, or light.

Example: The folding of leaves in Touch-me-not (Mimosa pudica) upon touch is due to such a mechanism.

•Common in plants like Mimosa, sunflowers, and venus flytrap.​
• Such movements are independent of growth and are reversible.
• No specialized nervous system is involved—plants rely on hormonal and chemical signals.
• It is a quick response mechanism for protection or adaptation.

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