Which of the following components make up an ecosystem?

Step 1: Analyze the question The question asks what the basic components of an ecosystem are.

Step 2: Explain the concept An ecosystem is a community of living organisms (biotic factors) interacting with each other and with their non-living (abiotic) environment, such as air, water, soil, light and temperature, as one functional unit.

So there are two broad components:

• Biotic (living): producers (plants), consumers (animals) and decomposers (bacteria, fungi)
• Abiotic (non-living): sunlight, water, soil, temperature, air, pH

Step 3: Evaluate the options

• A. Decomposers, animals and non-living factors: This leaves out plants (producers), so it is incomplete.
• B. Living and non-living factors: This covers every biotic and abiotic component, so it is complete and correct.
• C. Plants and non-living factors: This leaves out animals and decomposers.
• D. Plants, decomposers and non-living factors: This leaves out animals (consumers).

Options A, C and D each omit at least one group of living things. Only B is fully inclusive.

Step 4: Answer The correct option is B. Living and non-living factors.

Exam tip: Remember "Biotic + Abiotic = Ecosystem." When an option lists only some of the living groups, it is usually a distractor. Choose the option that covers everything.