How is an ecosystem defined?

An ecosystem is defined as a biological community interacting with its physical environment. This definition encompasses both the living organisms (the biotic components like plants, animals, fungi, and microorganisms) and the non-living elements (the abiotic components such as soil, water, air, and minerals) within a specific area. The interactions among these biotic and abiotic factors are crucial because they help regulate energy flow, nutrient cycling, and the overall functioning of the ecosystem.

The essence of an ecosystem lies in the dynamic interactions between organisms and their environment, which affects everything from population dynamics to community structure. These interactions can include predation, competition, symbiosis, and the utilization of resources, demonstrating the complexity and interdependence of life forms within a specific habitat.

In contrast, the other choices do not accurately capture the essence of an ecosystem. For instance, merely having a group of different organisms without interactions fails to recognize the crucial relationships that define an ecosystem. Similarly, a simple interaction of two species does not encompass the full complexity of ecological dynamics. Lastly, focusing solely on a living organism interacting with abiotic factors overlooks the significant roles that biotic interactions play in shaping ecosystems.