Plants have neither a nervous system nor muscles, even then they respond to stimuli. For example, the leaves of chhui-mui (touch-me-not) plant when touched begin to fold up and droop.
Generated by claude-sonnet-4-6 · 2026-06-15 06:48 · grounding rag
Model Answer
(a) In touch-me-not plants, information is communicated from cell to cell through electrical-chemical means. However, unlike animals, there is no specialised tissue for conduction of this information.
(b) Plant cells change their shape by changing the amount of water in them, resulting in swelling or shrinking. This change in turgor pressure enables the observable movement (folding/drooping of leaves).
(c) The movement of leaves in touch-me-not is independent of growth — it occurs due to change in water content in cells. The movement of tendrils in a pea plant is dependent on growth — it is a directional growth response (thigmotropism).
Source: Chapter 6, Section 6.2 and 6.2.1
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Explanation
- (a) Examiner wants the phrase "electrical-chemical means" and the point that no specialised tissue exists — both earn the mark.
- (b) Key term is turgor change / change in water content causing cells to swell or shrink. Don't write "proteins" here — that's for animal muscles.
- (c) The one-mark distinction is simply: sensitive plant movement = growth-independent; tendril movement = growth-dependent. Use these exact contrasting terms.