NEET · Biology —

Ecosystem appeared 3 times across 1 year — 3.3% of Biology. This question is from Decomposition.

Year 2024 Total
Questions 3 3
Practice all Ecosystem questions → View full NEET weightage & trends →

Match List I with List II:
List-IList-II
A. DecompositionI. Accumulation of dark coloured amorphous colloidal substance
B. DetritusII. Release of inorganic nutrients by the activity of microbes in soil
C. MineralisationIII. Breaking down of complex organic matter into inorganic substances.
D. HumificationIV. Dead remains of plants and animals including fecal matter
Choose the correct answer from the options given below:

Solution & Explanation

Core Logic
  • Decomposition (A) is the biological process of breaking down complex organic matter into inorganic substances (A-III).
  • Detritus (B) acts as the raw material for decomposition and includes dead remains of plants, animals, and fecal matter (B-IV).
  • Mineralisation (C) is the degradation of humus by microbes, releasing inorganic nutrients (C-II).
  • Humification (D) leads to the accumulation of a dark coloured amorphous substance called humus (D-I).
Step 1: Final Conclusion

The correct matches are A-III, B-IV, C-II, D-I.

Pattern Recognition

Humification explicitly forms 'Humus', which is the 'dark coloured amorphous' substance. D-I is uniquely distinguishing in some options, paired with A-III for Decomposition.

Chapter Mix

Class 12 Biology: Ecosystem

Reference Study Guides

Ecosystem

More Ecosystem Previous-Year Questions

Q94 neet_2026_03_may_morning Productivity
Match List I with List II :
List IList II
A. ProductivityI. Gross primary productivity minus respiration losses
B. Net primary productivityII. Rate of formation of new organic matter by consumers
C. Gross primary productivityIII. Rate of biomass production
D. Secondary productivityIV. Rate of production of organic matter during photosynthesis
Choose the correct answer from the options given below:
  • A. A-I, B-II, C-III, D-IV
  • B. A-III, B-I, C-IV, D-II
  • C. A-III, B-I, C-II, D-IV
  • D. A-I, B-III, C-IV, D-II

Solution

Core Logic

Let's align definitions:

  • Productivity (A): It is the general rate of biomass production. (A-III)
  • Net primary productivity (B): It is the Gross primary productivity (GPP) minus respiration losses (R). (B-I)
  • Gross primary productivity (C): The rate of production of organic matter during photosynthesis. (C-IV)
  • Secondary productivity (D): The rate of formation of new organic matter by consumers. (D-II)
Step 1: Final Conclusion

Matching them up gives A-III, B-I, C-IV, D-II.

Pattern Recognition

NPP = GPP - R is a fundamental equation. B matches with I immediately. Looking at the options, only two options have B-I. Secondary productivity specifically involves consumers (D-II), which isolates the correct option.

Chapter Mix

Class 12 Biology: Ecosystem

Q149 neet_2026_03_may_morning Ecological Pyramids
Ecological pyramids represent the relationship between the organisms at different trophic levels and they are generally inverted for:
  • A. Pyramid of energy in pond ecosystem
  • B. Pyramid of biomass in sea
  • C. Pyramid of number in grassland
  • D. Pyramid of biomass in grassland

Solution

Core Logic

Let's review the shape of various ecological pyramids:

  • Pyramid of Energy: ALWAYS upright in all ecosystems, as energy is lost as heat at each step (10% law).
  • Pyramid of Number in Grassland: Upright (millions of grass plants support fewer herbivores and even fewer carnivores).
  • Pyramid of Biomass in Grassland: Upright.
  • Pyramid of Biomass in Sea/Aquatic ecosystems: Generally inverted. The standing crop of phytoplankton (producers) has less biomass than the zooplankton and fish (consumers) they support due to their rapid turnover rate.
Step 1: Final Conclusion

The pyramid of biomass in a sea/aquatic ecosystem is the classic example of an inverted pyramid.

Pattern Recognition

Aquatic biomass pyramid = Inverted. Tree ecosystem number pyramid = Inverted/Spindle. Energy pyramid = Always upright.

Chapter Mix

Class 12 Biology: Ecosystem

More Ecosystem Questions — neet_2026_03_may_morning

Practice all Ecosystem previous-year questions →

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%)