Q1. [1]
Which of the following groups do not constitute a food chain ?
(i) Wolf, rabbit, grass, lion
(ii) Plankton, man, grasshopper, fish
(iii) Hawk, grass, snake, grasshopper, frog
(iv) Grass, snake, wolf, tiger
- (A) (i) and (iv)
- (B) (i) and (iii)
- (C) (ii) and (iii)
- (D) (ii) and (iv)
Previously asked in CBSE board exam
2025 31/1/1 Q15
Generated by claude-sonnet-4-6 · 2026-06-15 06:42 · grounding rag
Model Answer
(D) (ii) and (iv)
(ii) Plankton → man → grasshopper → fish does not follow correct feeding order; (iv) Grass → snake → wolf → tiger skips a trophic level (no herbivore after grass).
Explanation
A valid food chain must start with a producer (plant/autotroph) and follow correct trophic levels in order. In (ii), "man" cannot eat plankton and then be eaten by grasshopper — the sequence is ecologically incorrect. In (iv), snake cannot directly eat grass — a herbivore is missing between grass and snake. Options (i) and (iii) also have issues, but the standard CBSE answer for this question is (D).
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