Question

Which one of the following cannot be considered as a decomposer?
A. Fungi
B. Bacteria
C. Hyenas
D. Earthworms
E. Dung beetles

Answer 1

Hint: The process of breaking down complex organic substances into simpler substances by the action of microorganisms is known as decomposition. The microbes which are involved in the process of decomposition are known as decomposers.

Complete Answer:
The word decomposition means “to break down” and it is one of the significant processes of the ecosystem. The raw materials for decomposition are decaying as dead animals and plants serve as raw materials.

Option A: Fungi act as decomposers and they are also known as saprotrophs which recycle the nutrients in the ecosystem. They use enzymes which help in digestion of organic remains.

Option B: Bacteria play an important role as they help in decomposition of organic materials. They are involved in early stages of decomposition when levels of moisture are high.

Option C: Hyenas are carnivorous animals, i.e. they are meat-eating animals. They generally are involved in hunting of animals.

Option D: Earthworms are special groups of species which are involved in dead or decaying organic materials. They are an example of decomposers. They eat the organic matter and they break it into smaller pieces so that bacteria and fungi feed on it.

Option E: Dung beetles aerate and mic the soil and are also involved in increasing the organic matter of the soil. They are involved actively in the process of decomposition.

Thus, the correct option is C) Hyenas.

Note: The factors that affect the rate of decomposition are,
1. Temperature - Optimum temperature is required for the growth and activity of microbes.
2. Litter quality - The rate of decomposition depends upon the physical and chemical properties of litter like for example bryophytes are decomposed at a slower rate.
3. Moisture - Presence of moisture in soil is responsible for various physiological processes of microorganisms.
4. Aeration - The oxygen present in the soil helps in growth of microbes.