Which of the following best defines an ecosystem?

• A. A community of organisms interacting with each other and their physical environment
• B. A group of individuals of the same species living in the same area
• C. All the abiotic factors in a given region
• D. The process by which energy flows through a food chain

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by understanding the term 'ecosystem.' An ecosystem is a biological system that includes all living organisms (biotic factors) in a particular area, along with the non-living (abiotic) components of their environment, such as air, water, and soil, interacting as a system.
2. Step 2: Analyze the options provided. The first option mentions 'a community of organisms interacting with each other and their physical environment,' which aligns with the definition of an ecosystem. This includes both biotic and abiotic factors.
3. Step 3: Evaluate the second option, 'a group of individuals of the same species living in the same area.' This describes a population, not an ecosystem, as it focuses only on one species and does not include interactions with abiotic factors.
4. Step 4: Consider the third option, 'all the abiotic factors in a given region.' This refers only to the non-living components and excludes the biotic factors, so it does not define an ecosystem.
5. Step 5: Examine the fourth option, 'the process by which energy flows through a food chain.' While energy flow is a key process within an ecosystem, it does not encompass the full definition of an ecosystem, which includes both biotic and abiotic interactions.