Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Ecosystem

Question:

The rate of decomposition in a particular climatic condition is quicker, if detritus is rich in__________& __________

Options:

Sugars. Phosphorus

Lignin, Phosphorus

Sugars. Nitrogen

Lignin. Chitin

Correct Answer:

Sugars. Nitrogen

Explanation:

The correct answer is Option (3) - Sugars. Nitrogen

Decomposers break down complex organic matter into inorganic substances like carbon dioxide, water and nutrients and the process is called decomposition. Dead plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter, constitute detritus, which is the raw material for decomposition. The important steps in the process of decomposition are fragmentation, leaching, catabolism, humification and mineralisation.

Decomposition is largely an oxygen-requiring process. The rate of decomposition is controlled by chemical composition of detritus and climatic factors. In a particular climatic condition, decomposition rate is slower if detritus is rich in lignin and chitin, and quicker, if detritus is rich in nitrogen and water-soluble substances like sugars. Temperature and soil moisture are the most important climatic factors that regulate decomposition through their effects on the activities of soil microbes. Warm and moist environment favour decomposition whereas low temperature and anaerobiosis inhibit decomposition resulting in build up of organic materials