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Biology · 2025 · 2 marks
CBSE 2025 · Region 4 · Set 1 · Q21
(a) Explain how the interaction between sea anemone and clownfish is one of the best examples of commensalism in nature.
(a)
Explain how the interaction between sea anemone and clownfish is one of the best examples of commensalism in nature.
OR
(b)
Correctly depict (also indicate the trophic level) and describe the ecological pyramid of biomass in sea with $\displaystyle 40$ standing crop of phytoplankton supporting $\displaystyle 90$ standing crop of zooplankton which further supports $\displaystyle 120$ small fishes.
Marking-scheme solution
The clownfish gets protection from the predators due to the
presence of stinging tentacles thus deriving benefit from sea anemone, the sea anemone neither derive any benefit nor get harmed from the clownfish.
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CBSE Class 12 Biology past-paper question from the 2025 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.