What is geotropism? With the help of an example each, distinguish between positive geotropism and negative geotropism in plants.
Generated by claude-sonnet-4-6 · 2026-06-26 01:01 · grounding rag
Model Answer
Geotropism is the movement of a plant part in response to the force of gravity.
- Positive geotropism: Movement of a plant part towards gravity.
Example: Roots grow downward into the soil — they show positive geotropism.
- Negative geotropism: Movement of a plant part away from gravity.
Example: The stem grows upward against gravity — it shows negative geotropism.
When a seed germinates, the root grows down (positive geotropism) and the shoot grows up (negative geotropism), ensuring the plant is properly anchored and exposed to sunlight.
Source: Chapter 6, Section 6.2 – Coordination in Plants
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Explanation
- 1 mark for defining geotropism correctly (response to gravity).
- 1 mark for positive geotropism + example (root grows downward).
- 1 mark for negative geotropism + example (stem grows upward).
- Always mention direction (towards/away from gravity) — that's what distinguishes the two types.
- The passage mentions "the root goes down, the stem comes up" when a seed germinates — use this directly as your example.
- Do not confuse geotropism with phototropism (response to light).