Question

Which process of decomposition is correctly described?

• A. Leaching: Water soluble inorganic nutrients rise to the top layers of soil
• B. Fragmentation: Carried out by organisms such as earthworm
• C. Humification: Leads to accumulation of a dark coloured substance humus which undergoes microbial action at a very fast rate
• D. Catabolism: Last step in decomposition under fully anaerobic conditions

Answer 1

The correct option is B Fragmentation: Carried out by organisms such as earthworm

Decomposition is the process of breaking of complex organic matter into simpler inorganic matter. There are five steps of decomposition. These are fragmentation, leaching, catabolism, humification and mineralization. Fragmentation is the process of breaking of detritus into small pieces by detrivores such as earthworm.

Leaching is the process of releasing nutrients in the water and seeping into the soil.

Humification is the process of formation of dark colored substance humus on the soil. It undergoes microbial action at a slow rate. Mineralization is the process of degradation of the hummus to release inorganic nutrients.

Catabolism is the process of breaking down of complex molecules into the simpler molecules.

Thus, the correct answer is 'Fragmentation: Carried out by organisms such as earthworm.'