SSC Selection Post 2025 PYQ — Question 5

Correct Answer: Decomposers

Explanation

Organisms that break down dead organic matter, such as decaying plants and animals, are called Decomposers. They play a vital role in keeping an ecosystem healthy and balanced. When plants and animals die, decomposers secrete specialized digestive enzymes to break down this complex organic waste into simpler, inorganic nutrients like carbon, nitrogen, and phosphorus.

By breaking down dead matter, they return these essential nutrients back into the soil, water, and air, making them available once again for green plants to absorb. Without decomposers, dead organic material would accumulate continuously, and the nutrient cycle would grind to a halt, starving the rest of the food web. The most common examples of decomposers in nature are fungi, bacteria, and certain microscopic organisms.

Key Points

Producers, also known as autotrophs, are organisms like green plants and algae that manufacture their own food from sunlight, water, and carbon dioxide through the process of photosynthesis.

Consumers, or heterotrophs, are organisms that cannot synthesize their own food and must rely on eating plants or other animals to obtain their energy.

Parasites are organisms that live on or inside another living organism (the host) and derive nutrients at the host's direct expense, often causing harm or disease.

Important Questions and Answers

Question: Which two major taxonomic kingdoms of life contain the primary microscopic and macroscopic decomposers in terrestrial ecosystems?

Answer: The kingdoms of Fungi (mushrooms, molds) and Monera (bacteria) contain the primary decomposers.

Question: What is the main ecological difference between a decomposer and a detritivore like an earthworm?

Answer: Detritivores physically ingest and digest dead matter internally, whereas decomposers externally break down matter using chemical enzymes and absorb nutrients at a molecular level.