Ecosystem Previous Year Questions — NEET Biology

3 past-year Ecosystem questions from NEET (Biology).

Q94 (2024)

Match List I with List II : <div style="overflow-x: auto; margin: 1rem 0;"><table style="width: 100%; border-collapse: collapse; text-align: left; font-size: 14px;"><thead><tr><th style="border: 1px solid #888; padding: 8px;"></th><th style="border: 1px solid #888; padding: 8px;">List I</th><th style="border: 1px solid #888; padding: 8px;"></th><th style="border: 1px solid #888; padding: 8px;">List II</th></tr></thead><tbody><tr><td style="border: 1px solid #888; padding: 8px;">A.</td><td style="border: 1px solid #888; padding: 8px;">Productivity</td><td style="border: 1px solid #888; padding: 8px;">I.</td><td style="border: 1px solid #888; padding: 8px;">Gross primary productivity minus respiration losses</td></tr><tr><td style="border: 1px solid #888; padding: 8px;">B.</td><td style="border: 1px solid #888; padding: 8px;">Net primary productivity</td><td style="border: 1px solid #888; padding: 8px;">II.</td><td style="border: 1px solid #888; padding: 8px;">Rate of formation of new organic matter by consumers</td></tr><tr><td style="border: 1px solid #888; padding: 8px;">C.</td><td style="border: 1px solid #888; padding: 8px;">Gross primary productivity</td><td style="border: 1px solid #888; padding: 8px;">III.</td><td style="border: 1px solid #888; padding: 8px;">Rate of biomass production</td></tr><tr><td style="border: 1px solid #888; padding: 8px;">D.</td><td style="border: 1px solid #888; padding: 8px;">Secondary productivity</td><td style="border: 1px solid #888; padding: 8px;">IV.</td><td style="border: 1px solid #888; padding: 8px;">Rate of production of organic matter during photosynthesis</td></tr></tbody></table></div> Choose the correct answer from the options given below:
  1. A-I, B-II, C-III, D-IV
  2. A-III, B-I, C-IV, D-II
  3. A-III, B-I, C-II, D-IV
  4. A-I, B-III, C-IV, D-II
### Related Formula $NPP = GPP - R$ ### Core Logic - Productivity: Rate of biomass production $\rightarrow$ III - Net primary productivity: $GPP - R$ $\rightarrow$ I - Gross primary productivity: Rate of organic matter production during photosynthesis $\rightarrow$ IV - Secondary productivity: Rate of formation of new organic matter by consumers $\rightarrow$ II ### Step 1: Match Verification Matches: A-III, B-I, C-IV, D-II. Correct option is (2). ### Pattern Recognition NPP is always GPP minus respiration losses ($NPP = GPP - R$). B-I immediately singles out option (2) or (3). Secondary productivity is by consumers (D-II), confirming option (2). ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Biology: Ecosystem

Q99 (2024)

Match List I with List II: <div style="overflow-x: auto; margin: 1rem 0;"><table style="width: 100%; border-collapse: collapse; text-align: left; font-size: 14px;"><thead><tr><th style="border: 1px solid #888; padding: 8px;"></th><th style="border: 1px solid #888; padding: 8px;">List-I</th><th style="border: 1px solid #888; padding: 8px;"></th><th style="border: 1px solid #888; padding: 8px;">List-II</th></tr></thead><tbody><tr><td style="border: 1px solid #888; padding: 8px;">A.</td><td style="border: 1px solid #888; padding: 8px;">Decomposition</td><td style="border: 1px solid #888; padding: 8px;">I.</td><td style="border: 1px solid #888; padding: 8px;">Accumulation of dark coloured amorphous colloidal substance</td></tr><tr><td style="border: 1px solid #888; padding: 8px;">B.</td><td style="border: 1px solid #888; padding: 8px;">Detritus</td><td style="border: 1px solid #888; padding: 8px;">II.</td><td style="border: 1px solid #888; padding: 8px;">Release of inorganic nutrients by the activity of microbes in soil</td></tr><tr><td style="border: 1px solid #888; padding: 8px;">C.</td><td style="border: 1px solid #888; padding: 8px;">Mineralisation</td><td style="border: 1px solid #888; padding: 8px;">III.</td><td style="border: 1px solid #888; padding: 8px;">Breaking down of complex organic matter into inorganic substances.</td></tr><tr><td style="border: 1px solid #888; padding: 8px;">D.</td><td style="border: 1px solid #888; padding: 8px;">Humification</td><td style="border: 1px solid #888; padding: 8px;">IV.</td><td style="border: 1px solid #888; padding: 8px;">Dead remains of plants and animals including fecal matter</td></tr></tbody></table></div> Choose the correct answer from the options given below:
  1. A-I, B-II, C-III, D-IV
  2. A-IV, B-III, C-I, D-II
  3. A-III, B-IV, C-II, D-I
  4. A-III, B-II, C-I, D-IV
### Related Formula Decomposition processes: Fragmentation, Leaching, Catabolism, Humification, Mineralisation. ### Core Logic - Decomposition: Breaking down complex organic matter into inorganic substances $\rightarrow$ III - Detritus: Dead remains of plants/animals including fecal matter $\rightarrow$ IV - Mineralisation: Release of inorganic nutrients by microbial activity $\rightarrow$ II - Humification: Accumulation of dark coloured amorphous substance (humus) $\rightarrow$ I ### Step 1: Match Verification Correct match sequence: A-III, B-IV, C-II, D-I. Correct option is (3). ### Pattern Recognition Humification = Humus accumulation (D-I). Detritus = Dead remains (B-IV). Instantly isolates option (3). ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Biology: Ecosystem

Q149 (2024)

Ecological pyramids represent the relationship between the organisms at different trophic levels and they are generally inverted for:
  1. Pyramid of energy in pond ecosystem
  2. Pyramid of biomass in sea
  3. Pyramid of number in grassland
  4. Pyramid of biomass in grassland
### Related Formula $\text{Pyramid of Biomass in Sea: } \text{Biomass of Fishes (Consumers)} > \text{Biomass of Phytoplankton (Producers)} \rightarrow \text{Inverted}$ ### Core Logic The pyramid of biomass in a sea/aquatic ecosystem is generally inverted because the biomass of primary producers (phytoplankton) is small compared to that of consumers (zooplankton and fishes) due to the rapid turnover rate of phytoplankton. ### Step 1: Checking Other Options * Pyramid of energy is ALWAYS upright in all ecosystems. * Pyramid of number in grassland is upright. * Pyramid of biomass in grassland is upright. ### Pattern Recognition Sees: "inverted ecological pyramid". Shortcut: Pyramid of biomass in sea/ocean is inverted; Pyramid of energy is ALWAYS upright. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 12 Biology: Ecosystem
Rankbit System
JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%) | JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%)

Select Your Target Exam

Choose an exam track below to find formulas per chapter and patterns.

Syncing Exam Intelligence

Mapping formulas and patterns across all tracks…

PATH A — FULL LENGTH PRACTICE

Full Mock Test Hub

Simulate real NTA exam conditions with fully tracked mocks. Time yourself against past papers.

Now Live Open
PATH B — TARGETED PRACTICE

Topic-wise Practice Hub

Practice past-year questions one chapter at a time. Pick an exam → subject → chapter and get every PYQ for that topic — pulled together from all past papers — with the chapter's key formulas alongside.

Loading Questions... Browse Topics

Exam Analysis Tools

Chapter weightage trends and topic-wise practice — all mapped from past shift papers.

Year-wise PYQ

Chapter Weightage & Trends

See high-yield chapters, year-wise counts and the frequency-based chance each topic repeats next exam.

Weightage Board Open
Targeted PYQs

Topic-wise Practice Hub

Every past-year question for a chapter pulled from all papers, with its key formulas alongside.

One chapter at a time Open
Latest from the Blog
View all →

Loading articles...