Question

which statement best describes an ecosystem?
it is the number of individuals of a given species in a specific area at a certain time
it is a group of individuals of a population that depends on the same type of resources of a region
it is the interactive complex of one or more communities with abiotic environmental factors
it is the number of different populations in a specific area or region at a certain time

Explanation:

An ecosystem is defined as the interaction between living communities (biotic factors) and non - living environmental factors (abiotic factors). The first option describes population density, the second describes a niche within a population, and the last describes species richness.

Answer:

It is the interactive complex of one or more communities with abiotic environmental factors