Question

Which process of decomposition is correctly described?
a. Leaching: water soluble inorganic nutrients rise to the top layers of the soil.
b. Fragmentation: Carried out by organisms such as earthworm.
c. Humification: leads to accumulation of a dark coloured substances humus which undergoes microbial action at a very fast rate
d. Catabolism: Last step in decomposition under fully anaerobic conditions.

Answer 1

Hint: Fragmentation Is the process of breaking down different materials into smaller parts or fragments. This is also a process of asexual reproduction way of many organisms like algae. So, by breaking down into smaller unit decompositions can be done by bacteria and other organisms.

Complete answer:
> Option A, Leaching is a process where an ore is treated with chemicals to convert the valuable metals within the ore, into soluble salts but impurities remain insoluble.

> Option B, Fragmentation is a form f asexual reproduction in multi-cellular organisms. In this process the organisms like earthworm, hydra etc. split into fragments. It in general can be defined as a process of breaking down into smaller subunits so that it can be decomposed.

> Option C, Humification is a process of formation of organic matter that has reached maturity (also called humic substances) decomposed from plant remains.

> Option D, Catabolism is the process that breaks down molecules into smaller units by the set of metabolic pathways. Those smaller units that are either oxidized and release the energy or used in other anabolic reactions.

Thus, we can conclude that fragmentation is the process in which breakdown of materials is carried out by different organisms like earthworms.
Hence, the correct answer is option (B).

Note: The meaning of fragmentation is being broken into sections. For example the Spirogyra undergoes fragmentation which results in numbers of filaments and every filament grows into mature filament or organism. So, the meaning of fragmentation is different in different aspects.