Q1. [2] medium thorough-understanding
Why is it said that heterotrophic organisms depend directly or indirectly on autotrophs? Give one example each of direct and indirect dependence.
Generated by claude-sonnet-4-6 · 2026-06-15 06:45 · grounding rag
Model Answer
Heterotrophic organisms cannot prepare their own food and depend on autotrophs (green plants) as the ultimate source of energy and organic matter.
- Direct dependence: A cow (herbivore) directly eats grass (autotroph) for nutrition.
- Indirect dependence: A lion eats a deer, which had eaten grass — so the lion depends on autotrophs indirectly through the food chain.
Source: Life Processes, Section 5.2; Our Environment, Section 13.1.1
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Explanation
- The key phrase from the textbook is: "heterotrophs' survival depends directly or indirectly on autotrophs" — quote or paraphrase this for 1 mark.
- The second mark is for giving one example each of direct (herbivore → plant) and indirect (carnivore → herbivore → plant) dependence. Keep examples simple and from the food chain concept.
- Don't over-explain; two clear examples with one-line reasoning each is sufficient for a 2-mark answer.