In population ecology, which of the following groups of organisms best represents a population?

• A. All individuals of different species living in the same area at the same time
• B. All members of a species living on Earth regardless of location
• C. All organisms (living and nonliving factors) found within an ecosystem
• D. All individuals of the same species living in the same area at the same time

Answer: (D)

Verified step by step guidance

1. Understand the definition of a population in ecology: a population consists of all individuals of the same species living in a specific area at the same time.
2. Analyze each option by comparing it to this definition:
3. Option 1: 'All individuals of different species living in the same area at the same time' includes multiple species, so it represents a community, not a population.
4. Option 2: 'All members of a species living on Earth regardless of location' describes the entire species globally, which is larger than a population and is called the species' range or global population.
5. Option 3: 'All organisms (living and nonliving factors) found within an ecosystem' includes both biotic and abiotic components, which defines an ecosystem, not a population.