Which term describes all populations living together in a given area?

• A. Community
• B. Estuary
• C. Turbidity
• D. Light

Answer: (A)

In ecology, a community is all populations of different species living together in a defined area and interacting with one another. This captures the whole biotic side of that space—predation, competition, mutualism, and other relationships among species—rather than focusing on a single species or on the physical environment. For example, in a forest community you’d include trees, understory plants, fungi, insects, birds, and mammals all coexisting and interacting. The other terms describe something different: an estuary is a habitat at the freshwater–marine boundary, turbidity is about water clarity (an abiotic condition), and light is an abiotic resource affecting photosynthesis.