With reference to the food chains in ecosystems, which of the following kinds of organism is / are known as decomposer organism/organisms?

1. Virus

2. Fungi

3. Bacteria

Select the correct answer using the codes given below.

This question was previously asked in
OPSC OAS (Preliminary) Exam (GS) Official Paper-I (Held On: 15 Dec, 2024)
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  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3

Answer (Detailed Solution Below)

Option 2 : 2 and 3 only
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Detailed Solution

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The correct answer is 2 and 3 only.

Key Points

  • Fungi and bacteria are known as decomposer organisms.
  • They play a crucial role in breaking down dead organic material and recycling nutrients back into the ecosystem.
  • Decomposers are essential for the decomposition process, which ensures the continuous availability of nutrients for plants and other organisms.
  • Viruses are not considered decomposers as they do not break down organic material.

Additional Information

  • Decomposers
    • Decomposers are organisms that break down dead or decaying organisms and waste products, contributing to the recycling of nutrients in ecosystems.
    • They convert complex organic substances into simpler inorganic substances, which can be taken up and used by plants.
    • Fungi and bacteria are the primary decomposers in many ecosystems, playing a vital role in nutrient cycling and energy flow.
  • Fungi
    • Fungi are a kingdom of spore-producing organisms that feed on organic matter, including molds, yeast, mushrooms, and toadstools.
    • They are essential decomposers in ecosystems, breaking down complex organic substances into simpler compounds.
    • Fungi release enzymes that digest organic material externally, and then absorb the resulting small nutrient molecules.
  • Bacteria
    • Bacteria are single-celled microorganisms that can be found in almost every environment on Earth.
    • Many bacteria are decomposers that break down organic matter, releasing nutrients back into the environment for use by other organisms.
    • Bacteria play a key role in processes such as nitrogen fixation, decomposition, and nutrient cycling.
  • Virus
    • Viruses are microscopic infectious agents that can only replicate inside the living cells of organisms.
    • They are not considered decomposers because they do not break down organic material or contribute to nutrient cycling.
    • Viruses infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea.
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