How are populations, ecosystems, and communities related? (1 point)
a community consists of an ecosystem and its physical environment, and an ecosystem is made up of many different populations of organisms.
a population consists of a community of organisms and its physical environment, and a community is made up of many different ecosystems.
an ecosystem consists of a community of organisms and its physical environment, and a community is made up of many different populations of organisms.
an ecosystem consists of a population of organisms and its physical environment, and a population is made up of many different communities of organisms.

The correct answer is An ecosystem consists of a community of organisms and its physical environment, and a community is made up of many different populations of organisms.  

When living organisms ( like plants and animals) interact with each other and their environment ( non living factors), they constitute an ecosystem.

Community in an ecosystem is defined as the group of populations of different species, which are present in a particular area. Population is a group of living organisms belonging to the same species.

Thus, population makes community and community makes ecosystem.

Therefore, an ecosystem consists of a community of organisms and its physical environment, and a community is made up of many different populations of organisms.