Question

Decomposition is a type of ______

• A. aerobic respiration
• B. anaerobic respiration
• C. exothermic reaction
• D. none of these.

Answer 1

The correct option is A aerobic respiration

When organic materials decompose in the presence of oxygen, the process is called “aerobic.” The aerobic process is most common in nature. For example, it takes place on ground surfaces such as the forest floor, where droppings from trees and animals are converted into relatively stable humus. There is no accompanying bad smell when there is adequate oxygen present. In aerobic decomposition, living organisms, which use oxygen, feed upon the organic matter. They use the nitrogen, phosphorus, some of the carbon, and other required nutrients. Much of the carbon serves as a source of energy for the organisms and is burned up and respired as carbon dioxide. Since carbon serves both as a source of energy and as an element in the cell protoplasm, much more carbon than nitrogen is needed. Generally, about two-thirds of carbon is respired as $C{0}_2$, while the other third is combined with nitrogen in the living cells. However, if the excess of carbon over nitrogen (C: N ratio) inorganic materials being decomposed is too great, biological activity diminishes. Several cycles of organisms are then required to burn most of the carbon.

So, the correct answer is A.