Science (086) — AI-generated practice question

(i) Two Categories of Plant Movement:

Growth-independent movement: When the leaves of a sensitive plant (Mimosa pudica) are touched, they fold and droop rapidly. No growth is involved. The plant communicates the touch stimulus cell to cell using electrical-chemical signals. Cells then change shape by changing the amount of water in them (swelling or shrinking), causing movement.

Growth-dependent movement: The directional growth of a seedling (e.g., stem growing upward toward light — phototropism) is caused by growth. If growth is prevented, movement does not occur.

(ii) Four Plant Hormones:

| Hormone | Promotes/Inhibits | Specific Function |
|---|---|---|
| Auxin | Promotes | Causes phototropism by promoting cell elongation on the shaded side |
| Gibberellin | Promotes | Promotes stem elongation and seed germination |
| Cytokinin | Promotes | Promotes cell division |
| Abscisic acid | Inhibits | Promotes wilting of leaves; inhibits growth under stress |

Source: Chapter 6, Section 6.2 and 6.2.1

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• The passage explicitly states the two movement types — examiners expect both named and explained with examples.
• The mechanism for growth-independent movement (water movement in cells) is directly from Section 6.2.1 — quote this closely.
• For hormones, the textbook lists auxin, gibberellin, cytokinin, and abscisic acid. Abscisic acid is the main inhibitor. Memorise one function each — examiners check specificity.
• The table format is acceptable and saves space in a 5-mark answer.