In marine ecology, which term describes the physical setting used by an organism to survive?

• A. Habitat
• B. Intertidal Zone
• C. Niche
• D. Population

Answer: (A)

The main idea is the physical setting an organism uses to survive. Habitat refers to that environment—the combination of physical conditions (like temperature, salinity, depth, substrate) and the resources and shelter it provides that support the organism’s survival and reproduction. In marine systems, examples include coral reefs, kelp forests, seagrass beds, or the open water column, each offering different conditions and resources. This is different from a niche, which is about the organism’s role and how it interacts with other living things and uses resources within that setting, and from a population, which is just a group of individuals of the same species in an area. So the term that best describes the physical setting used by an organism to survive is habitat.