How is an ecosystem best described?

An ecosystem is best described as a system of living organisms and their non-living environment. This definition encompasses the complex interactions between biotic components, such as plants, animals, and microorganisms, with abiotic factors like soil, water, air, and climate. In an ecosystem, these living and non-living elements interact with each other, creating a dynamic system that supports life. For instance, plants (producers) convert sunlight into energy, animals (consumers) obtain energy by consuming plants or other animals, and decomposers break down dead organic material, returning nutrients to the soil.

The interplay between these components allows ecosystems to function and sustain biodiversity. Thus, this option captures the holistic nature of ecosystems and their essential characteristics.