The correct option is Fungi
Explanation
An ecosystem is a functional unit of nature consisting of two main structural components that interact with each other:
- Abiotic C These are non-living physical and chemical factors, such as light, temperature, water, soil, and atmospheric gases.
- Biotic Components: These are living organisms, which are further classified based on their nutritional roles into producers (autotrophs), consumers (heterotrophs), and decomposers (saprotrophs).
Option Analysis
- Fungi Fungi - Correct: Fungi are living organisms belonging to the Kingdom Fungi. In an ecosystem, they primarily act as decomposers. They break down dead organic matter into simpler inorganic substances, making them a crucial biotic component.
- Soil Soil - Incorrect: Soil is an abiotic (edaphic) factor. While it supports life and contains living organisms, the soil matrix itself (minerals, organic matter, air, water) is non-living.
- Water Water - Incorrect: Water is an inorganic chemical compound ($H_2O$) and is classified as an abiotic factor. It is essential for life but is not a living entity.
- Light Light - Incorrect: Light (specifically sunlight) is a climatic abiotic factor that provides energy for photosynthesis. It is a physical phenomenon, not a biological organism.
Key Takeaway
Biotic components refer to all living entities in an ecosystem (plants, animals, microbes), whereas Abiotic components refer to the non-living physical and chemical environment (soil, water, air, light, temperature) that sustains life.