Decomposition

Pheretima and its close relatives derive nourishment from:

1. Sugarcane roots

2. Decaying fallen leaves and soil organic matter

3. Soil insects

4. Small pieces of fresh fallen leaves of maize

Which one of the following processes during decomposition is correctly described?

1.	Humanification-Leads to the accumulation of a dark-coloured substance in humans which undergoes microbial action at a very fast rate
2.	Catabolism-Last step decomposition under fully anaerobic condition
3.	Leaching-Water soluble inorganic nutrients rise to the top layers of the soil
4.	Fragmentation-Carried out by organisms such as earthworms

The rate of decomposition is faster in the ecosystem due to the following factors, except:

1.	Detritus rich in sugars
2.	Warm and moist environment
3.	Presence of aerobic soil microbes
4.	Detritus richer in lignin and chitin

Given below are two statements:

Statement I:	Decomposition is a process in which the detritus is degraded into simpler substances by microbes.
Statement II:	Decomposition is faster if the detritus is rich in lignin and chitin.

In light of the above statements, choose the correct answer from the options given below:

1.	Statement I is incorrect but Statement II is correct.
2.	Both Statement I and Statement II are correct.
3.	Both Statement I and Statement II are incorrect.
4.	Statement I is correct but Statement II is incorrect.

Detritivores breakdown detritus into smaller particles. This process is called:

1. Decomposition	2. Catabolism
3. Fragmentation	4. Humification

Identify the correct statements:

A:	Detrivores perform fragmentation.
B:	The humus is further degraded by some microbes during mineralization.
C:	Water soluble inorganic nutrients go down into the soil and get precipitated by a process called leaching.
D:	The detritus food chain begins with living organisms.
E:	Earthworms break down detritus into smaller particles by a process called catabolism.

Choose the correct answer from the options given below:

1.	D, E, A only	2.	A, B, C only
3.	B, C, D only	4.	C, D, E only