Monera, Protists, Fungi, Plants, and Animals. Monera are microscopic organisms like bacteria. Protists are single-celled microscopic organisms like amoebae. Fungi are mullticellular organisms like mushrooms that live on other plants and animals. Plants are multicellular, have a rigid cell wall and make their own food.
Animals are multicellular, and they rely either directly or indirectly on other organisms for food.
Within each kingdom, there are thousands of species. A species is a group of living organisms that can breed and reproduce offspring. For example, a beaver is a species. It can breed with other beavers and produce more beavers. Scientists have a system for naming all the living organisms on earth.