3. What is an ecosystem? Any group of living and nonliving things interacting with each other can be considered as an ecosystem.

4. Ecosystems vary in size. They can be as small as a puddle or as large as the Earth itself. What kind of living things (organisms) could live in a puddle of water?

5. This pond is an ecosystem. Many living things (organisms) and nonliving things interact here. For example, the flowers are living things that depend upon the soil for minerals to grow. The flowers and the soil interact. Write about another example of living and nonliving things that interact in this ecosystem.

6. A great variety of organisms can be found in some ecosystems. Many populations are part of the ecosystem. A population is a group of organisms of one species that live in the same ecosystem. How many different populations do you see in this underwater ecosystem?

7. A community is made up of all the populations in an area. Members of a community depend upon each other to fill needs, like food, shelter, and reproduction. The wolves and deer here represent two populations that interact. How do they interact?