Biology Marking Period 2 Test Practice 2026 - Free Biology Test Practice Questions and Study Guide

A community is the group of populations of different species living together in a defined area, interacting with one another. This captures how many species coexist in one place and influence each other through feeding, competition, and relationships like predation or mutualism. A population, by contrast, refers to all individuals of a single species in that area. An ecosystem includes both the living community and the nonliving environment (air, water, soil, climate). Symbiosis is a specific type of relationship between two species, not the entire assemblage. So the description matches a community.