CBSE 2025 · Region 2 · Set 2 · Q21 · 2 marks
Student to attempt either option (A) or (B).Construct a pyramid of biomass starting with phytoplankton, label its three trophic levels. Is the pyramid upright or inverted ? Justify your answer.Draw a pyramid of number where a large population of insects feed upon a very big tree. The insects in turn, are eaten by small birds which in turn are fed upon by big birds.
Student to attempt either option (A) or (B).
Construct a pyramid of biomass starting with phytoplankton, label its three trophic levels. Is the pyramid upright or inverted ? Justify your answer.
Draw a pyramid of number where a large population of insects feed upon a very big tree. The insects in turn, are eaten by small birds which in turn are fed upon by big birds.
Marking-scheme solution
• Inverted pyramid of biomass
• The Biomass of fishes is much more than that of zooplankton and phytoplankton so the pyramid is inverted.
EcosystemEcological PyramidsApplyvery_short_answermedium
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CBSE Class 12 Biology past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.