Question

Which one of the following options represents the steps of decomposition in sequence?

• A. Fragmentation $\rightarrow$ Humification $\rightarrow$ Leaching $\rightarrow$ Catabolism $\rightarrow$ Mineralization
• B. Fragmentation $\rightarrow$ Leaching $\rightarrow$ Catabolism $\rightarrow$ Humification $\rightarrow$ Mineralization
• C. Fragmentation $\rightarrow$ Humification $\rightarrow$ Mineralization $\rightarrow$ Leaching $\rightarrow$ Catabolism
• D. Fragmentation $\rightarrow$ Catabolism $\rightarrow$ Humification $\rightarrow$ Mineralization $\rightarrow$ Leaching

Hint:

Use the mnemonic F-L-C-H-M: {F}rogs {L}ike {C}atching {H}uge {M}oths (Fragmentation, Leaching, Catabolism, Humification, Mineralization).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept: Decomposition is the process by which complex organic detritus is broken down into simpler inorganic substances. It involves several distinct, overlapping steps.
Step 2: Key Formula or Approach: Recall the chronological sequence of physical and chemical processes that detritus undergoes in an ecosystem.
Step 3: Detailed Explanation: The process begins with Fragmentation, where detritivores (like earthworms) physically break down large pieces of detritus into smaller particles.
Next, water-soluble inorganic nutrients wash down into the soil horizon and precipitate as unavailable salts. This step is called Leaching.
Bacterial and fungal enzymes then further chemically degrade the remaining detritus into simpler inorganic substances; this is termed Catabolism.
These three processes operate simultaneously on the detritus. As it decomposes, it transforms into a dark, amorphous substance through Humification.
Finally, this humus is further degraded by some microbes to release inorganic nutrients, completing the cycle in a step called Mineralization.
Therefore, the correct standard sequence is Fragmentation $\rightarrow$ Leaching $\rightarrow$ Catabolism $\rightarrow$ Humification $\rightarrow$ Mineralization.
Step 4: Final Answer: The correct sequence corresponds to option (2).