Which of the following statements are correct regarding decomposition?
A. Decomposition is largely oxygen-requiring process
B. The rate of decomposition is controlled by chemical composition of detritus and climatic factors
C. Dry and cold environment favour the decomposition
D. If detritus is rich in lignin and chitin, the decomposition rate is faster
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A and B only
A. Decomposition is largely oxygen-requiring process — Correct. Most decomposers respire aerobically, so a lack of oxygen slows decomposition.
B. The rate of decomposition is controlled by chemical composition of detritus and climatic factors — Correct. Both what the detritus is made of and the temperature and moisture decide the speed.
C. Dry and cold environment favour the decomposition — Incorrect. This reverses it: warm and moist conditions favour decomposition, while low temperature and dryness slow it.
D. If detritus is rich in lignin and chitin, the decomposition rate is faster — Incorrect. Lignin and chitin are tough; such detritus breaks down slowly. Detritus rich in nitrogen and sugars breaks down fast.
NCERT Extract:
Decomposition – “… 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.”