Q1. [1] § 5.2.3 How do Organisms obtain their Nutrition?
Assertion (A) : Amoeba takes in food using finger like extensions of the cell surface.
Reason (R) : In all unicellular organisms, the food is taken in by the entire cell surface.
- (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of (A).
- (b) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of (A).
- (c) Assertion (A) is true, but Reason (R) is false.
- (d) Assertion (A) is false, but Reason (R) is true.
Previously asked in CBSE board exam
2023 31/6/1 Q19
Generated by claude-sonnet-4-6 · 2026-06-11 09:47 · grounding rag
Model Answer
(c) Assertion (A) is true, but Reason (R) is false.
Amoeba does use finger-like extensions (pseudopodia) to take in food, but not all unicellular organisms take in food by the entire surface — Paramoecium, for example, takes in food at a specific spot.
Explanation
- A is true: The passage explicitly states "Amoeba takes in food using temporary finger-like extensions of the cell surface."
- R is false: The passage says food may be taken in by the entire surface in single-celled organisms, but Paramoecium (also unicellular) takes food in at a specific spot — disproving the absolute claim in R.
- Examiners expect you to spot the word "all" in the Reason as the flaw; generalisations like "all unicellular organisms" are often incorrect in assertion-reason questions.
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