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The rate of formation of new… (Class 12 Biology 2024, Q12)

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BiologyCBSE Class 12 · Board exam 2024, set 57/1/1 · 1 mark · MCQ

CBSE Class 12 Biology 2024: question 12

Set in the CBSE Class 12 board exam of 2024, paper 57/1/1, section A, question 12, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q12 · 1 mark · MCQEcosystem

The rate of formation of new organic matter by consumers, and the biomass available for consumption of herbivores as well as decomposers are referred to as :

  1. (A)Gross primary productivity and Net primary productivity
  2. (B)Net primary productivity and Secondary productivity
  3. (C)Secondary productivity and Net primary productivity
  4. (D)Secondary productivity and Gross primary productivity

Source: official question paper from cbse.gov.in (PDF). See it in the full 2024 board paper, set 57/1/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

Consumers carry out secondary production.

Hint 2

Producers' respiration losses are removed before biomass is passed on.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. The rate of formation of new organic matter by consumers is secondary productivity.

    ½ mark

  2. The biomass available to herbivores and decomposers is net primary productivity (GPP minus respiration loss).

    ½ mark

Answer: (C)

Where the marks are

  • Correctly names both terms (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Ecosystem, one at a time, marked against the answer key and marking points.Back to the full paper2024 board paper, set 57/1/1: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.