Each group has its own identifiable characteristics. All the groups have some things in common. For example, all living things are made up of cells. This chapter reviews the classification of living things. All living things depend on each other to live.
Plants are the only organisms which can make their own food.
Other organisms depend on others to produce their food. This means that all of them eventually depend on plants. This chapter reviews producers, consumers, food chains, population, and habitat, as well as showing how organisms depend on each other. All organisms in a community affect each other in some way, but people have a more lasting effect on their community than any other organisms. People add pollution to the environment which may destroy the habitat of other organisms.