Unicellular life refers to organisms that are composed of a single cell, such as amoebae. Amoebae are a type of protozoan, which are single-celled eukaryotes that lack a cell wall and can move by extending their pseudopods. They are found in a variety of habitats, including freshwater, marine, and soil environments. Amoebae are able to feed on bacteria and other small organisms, and they reproduce asexually by dividing into two daughter cells.