Question

Match 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 activity of microbes in soil
C. Mineralisation   III. Breaking down of complex organic matter into inorganic substances
D. Humification     IV. Dead remains of plants and animals including fecal matter

Choose the correct answer from the options given below :

• A. A-III, B-II, C-I, D-IV
• B. A-I, B-II, C-III, D-IV
• C. A-IV, B-III, C-I, D-II
• D. A-III, B-IV, C-II, D-I

Hint:

Remember the order: Fragmentation $\rightarrow$ Leaching $\rightarrow$ Catabolism $\rightarrow$ Humification $\rightarrow$ Mineralisation.

Answer 1

The Correct Option is D

Step 1: Understanding the Question
The goal is to match technical terms related to ecosystem nutrient cycling and soil formation with their correct descriptions. This involves understanding how dead matter is broken down into its basic components. Step 2: Key Formula or Approach
Analyze the stages of decomposition.
- Detritus is the starting material.
- Humification creates humus.
- Mineralisation releases raw minerals.
- Decomposition is the whole process.
Step 3: Detailed Explanation
A. Decomposition: This is the general process where decomposers convert complex organic molecules into simpler inorganic nutrients. Thus, A matches with III.
B. Detritus: This refers to the raw organic waste of an ecosystem—dead leaves, animal carcasses, and fecal matter. Thus, B matches with IV.
C. Mineralisation: This is the process where inorganic nutrients (like Nitrogen or Phosphorus) are released back into the soil by microbial action on humus. Thus, C matches with II.
D. Humification: This leads to the formation of humus, a dark-colored, amorphous, and nutrient-rich substance that is highly resistant to microbial breakdown. Thus, D matches with I.
Step 4: Final Answer
The correct sequence is A-III, B-IV, C-II, D-I. This is provided in option (B).