Which term refers to the number of organisms inhabiting a specific area?

The term that refers to the number of organisms inhabiting a specific area is population. In biological terms, a population is defined as a group of individuals of the same species that live in a particular area at the same time. The concept of population is essential in ecology as it helps scientists understand how species interact with their environment and with each other.

Density, while related, specifically refers to how many individuals there are per unit of area, which is a different aspect altogether. Community refers to all the different populations of various species that live together in a given area, emphasizing interactions among multiple species rather than focusing on a single species. An ecosystem encompasses not only the living organisms (the community) but also their physical environment and how they interact with it. Therefore, population is the correct answer as it specifically describes the count of organisms of one species in a defined area.