Taxonomy Scientists have classified all living things into five categories or kingdoms . One of Five All life on earth falls into one of five categories. 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.