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Ecosystem: NEET previous year questions

Every Ecosystem question from the official NEET papers on this site, with the answer and a worked solution.

The questions come from NEET 2026, Re-NEET 2026 and NEET 2020. Each shows its answer and solution when you open it, so you can attempt it first. For what the chapter covers and how NEET tests it, see the Ecosystem guide.

Practise on the CBT screen7 questions, 7 minutes, marked +4 / −1Download PDF4 pages, 0.7 MB, with answers and solutions

NEET 2026 · the full paper

  1. NEET 2026 · Q96

    Match List-I with List-II and choose the correct answer from the options given below:

    List I

    List II

    P) Productivity

    I) Gross primary productivity minus respiration losses

    Q) Net primary productivity

    II) Rate of formation of new organic matter by consumers

    R) Gross primary productivity

    III) Rate of biomass production

    S) Secondary productivity

    IV) Rate of production of organic matter during photosynthesis

    1. (1)

      P-III, Q-I, R-IV, S-II

    2. (2)

      P-I, Q-II, R-III, S-IV

    3. (3)

      P-I, Q-III, R-IV, S-II

    4. (4)

      P-III, Q-I, R-II, S-IV

    Answer and solution

    Answer: (1)

    Productivity is the rate of biomass production ; net primary productivity equals gross primary productivity minus respiration losses ; gross primary productivity is the rate of organic matter production during photosynthesis ; and secondary productivity is the rate of formation of new organic matter by consumers . This matches P-III, Q-I, R-IV, S-II.

  2. NEET 2026 · Q105

    Match List-I with List-II and choose the correct answer from the options given below:

    List I

    List II

    P) Decomposition

    I) Accumulation of dark coloured amorphous colloidal substance

    Q) Detritus

    II) Release of inorganic nutrients by the activity of microbes in soil

    R) Mineralisation

    III) Breaking down of complex organic matter into inorganic substances.

    S) Humification

    IV) Dead remains of plants and animals including fecal matter

    1. (1)

      P-IV, Q-III, R-I, S-II

    2. (2)

      P-III, Q-IV, R-II, S-I

    3. (3)

      P-I, Q-II, R-III, S-IV

    4. (4)

      P-III, Q-II, R-I, S-IV

    Answer and solution

    Answer: (2)

    Decomposition is the breaking down of complex organic matter into inorganic substances; detritus is the dead remains of plants and animals including faecal matter; mineralisation is the release of inorganic nutrients by microbial activity in soil; and humification is the accumulation of the dark-coloured amorphous colloidal humus. This gives P-III, Q-IV, R-II, S-I.

  3. NEET 2026 · Q173

    Ecological pyramids represent the relationship between the organisms at different trophic levels and they are generally inverted for:

    1. (1)

      Pyramid of number in grassland

    2. (2)

      Pyramid of energy in pond ecosystem

    3. (3)

      Pyramid of biomass in grassland

    4. (4)

      Pyramid of biomass in sea

    Answer and solution

    Answer: (4)

    Pyramids of number and biomass in grassland are upright, and the pyramid of energy is always upright. Inversion typically occurs for the pyramid of biomass in a sea/aquatic ecosystem, because the standing biomass of the phytoplankton (producers) at any moment is smaller than that of the zooplankton and consumers they support. Hence the pyramid of biomass in sea is inverted.

Re-NEET 2026 · the full paper

  1. Re-NEET 2026 · Q146

    Which of the following are primary consumers in a food chain?

    1. (1)

      Parasites

    2. (2)

      Predators

    3. (3)

      Herbivores

    4. (4)

      Carnivores

    Answer and solution

    Answer: (3)

    Primary consumers occupy the second trophic level and feed directly on the producers, which makes them by definition the herbivores. Carnivores that eat herbivores are secondary consumers at the third trophic level, and those that eat secondary consumers are tertiary. NCERT Class 12, Ecosystem.

  2. Re-NEET 2026 · Q178

    Which of the following statements are Correct ?

    Statement I: Energy flow from producers to consumers is unidirectional
    Statement II: Energy pyramid can never be inverted
    Statement III: Transfer of energy follows the 1% law

    Choose the correct answer from the options given below :

    1. (1)

      (I), (II) and (III)

    2. (2)

      (I) and (II) only

    3. (3)

      (I) and (III) only

    4. (4)

      (II) and (III) only

    Answer and solution

    Answer: (2)

    Energy enters an ecosystem as sunlight and moves in one direction only, from producers to successive consumer levels, being lost as heat at each step - it is never recycled the way nutrients are, so (Statement I) is correct. Because of that unavoidable loss, each level holds less energy than the one below it, so the pyramid of energy is ALWAYS upright and can never be inverted, making (Statement II) correct. Statement III misquotes Lindeman's rule, which is the 10 PER CENT law, not 1 per cent. NCERT Class 12, Ecosystem.

NEET 2020 · the full paper

  1. NEET 2020 · Q53

    In relation to Gross primary productivity and Net primary productivity of an ecosystem, which one of the following statements is correct?

    1. (1)

      Gross primary productivity is always more than net primary productivity

    2. (2)

      Gross primary productivity and Net primary productivity are one and same

    3. (3)

      There is no relationship between Gross primary productivity and Net primary productivity

    4. (4)

      Gross primary productivity is always less than net primary productivity

    Answer and solution

    Answer: (1)

    Gross primary productivity (GPP) is the total amount of energy fixed by photosynthesis, while net primary productivity (NPP) is GPP minus the energy used by plants for respiration. Therefore, GPP is always more than NPP. Chapter: Ecosystem.

  2. NEET 2020 · Q61

    Match the trophic levels with their correct species examples in a grassland ecosystem.

    List I

    List II

    P) Fourth trophic level

    I) Crow

    Q) Second trophic level

    II) Vulture

    R) First trophic level

    III) Rabbit

    S) Third trophic level

    IV) Grass

    1. (1)

      P-III, Q-II, R-I, S-IV

    2. (2)

      P-IV, Q-III, R-II, S-I

    3. (3)

      P-I, Q-II, R-III, S-IV

    4. (4)

      P-II, Q-III, R-IV, S-I

    Answer and solution

    Answer: (4)

    Grass is the first trophic level, rabbit the second, crow the third and vulture the fourth. Thus P-II, Q-III, R-IV, S-I. Chapter: Ecosystem.

Practise Ecosystem in the app: it brings back the questions you get wrong, so the chapter improves, not just your memory of these. Or try the free CBT mock. All chapters: NEET chapter-wise PYQs.

Questions

Are these the official NEET questions on Ecosystem?

Yes. They are the questions NTA set in each paper, in its wording. The solutions are written by BrainIt.

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