Ecosystems, Habitats, and Organisms
These pictures will show you examples of each ecosystem. The fourth picture, is levels of an ecosystem. It shows you where it starts, and where it is at the maximum.
There are many organisms inside of an ecosystem. They all have a role or niche. A niche is the role that the organism plays. One example would be like like a shark, inside of its marine ecosystem. Its habitat would be the open ocean, where it feeds upon smaller organisms. Its role or niche is to keep other marine animal populations from getting to big. If all of the sharks died out in the ocean, we would have an overpopulation on fish and other smaller marine organisms.