Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETBotanyEcosystem

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In a terrestrial ecosystem, if the Net Primary Productivity (NPP) of the producers is 20,000 J , the energy available to the tertiary consumers will be 20 J . Reason (R): According to the 10% law, only 10% of the energy is transferred from a lower trophic level to the next higher trophic level. In

Options

  1. ABoth Assertion and Reason are true and Reason is the correct explanation of Assertion.
  2. BBoth Assertion and Reason are true but Reason is not the correct explanation of Assertion.
  3. CAssertion is false but Reason is true.
  4. DAssertion is true but Reason is false.

Correct answer

C. Assertion is false but Reason is true.

Step-by-step solution

The Net Primary Productivity (NPP) of the producers (1st trophic level) represents the total biomass available for consumption by the primary consumers (2nd trophic level). Therefore, the energy available to the primary consumers is 20,000 J . According to the 10% law, only 10% of the energy is transferred to each subsequent trophic level. The Reason statement correctly defines this law. Applying the 10% law: Energy available to secondary consumers (3rd trophic level) = 10% of 20,000 J = 2000 J . Energy available t

Practice Ecosystem on Quantrex Academy →

More from Ecosystem

Match List I with List II : List I List II A. Productivity I. Gross primary productivity minus respiration losses B. Net primary productivity II. Rate of formation of new organic m 2026Ecological pyramids represent the relationship between the organisms at different trophic levels and they are generally inverted for : 2026Which of the following statements are correct ? (a) Energy flow from producers to consumers is unidirectional (b) Energy pyramid can never be inverted (c) Transfer of energy follow 2026Which of the following are primary consumers in a food chain ? 2026Match List I with List II : List I List II A. Decomposition I. Accumulation of dark coloured amorphous colloidal substance B. Detritus II. Release of inorganic nutrients by the act 2026Which of the following is the unit of productivity of an Ecosystem? 2025Given below are two statements: Statement I : The primary source of energy in an ecosystem is solar energy. Statement II : The rate of production of organic matter during photosynt 2025Given below are two statements: Statement I: In ecosystem, there is unidirectional flow of energy of sun from producers to consumers. Statement II: Ecosystems are exempted from 2nd 2025 Full Ecosystem list All NEET PYQs