What best describes the role of population in ecology?

The role of population in ecology is best described as the number of a given species in a particular area. This definition captures the concept of population dynamics, which involves studying how these numbers change over time due to births, deaths, immigration, and emigration. Understanding population size is crucial for assessing the viability of a species, its interactions within the ecosystem, and its overall health.

In ecological studies, the population of a species can directly influence various ecological functions, such as competition for resources, reproduction rates, and interactions with other species, shaping the entire ecosystem's balance. Focusing on population size allows ecologists to track changes in biodiversity, examine the impacts of environmental changes or human activities, and devise conservation strategies where needed.