Anatomy: An amoeba consists of a single blobby cell surrounded by a porous cell membrane. The amoeba "breathes" using this membrane - oxygen gas from the water passes in to the amoeba through the cell membrane and carbon dioxide gas leaves through it. A complex, jelly-like series of folded membranes called cytoplasm fills most of the cell. A large, disk-shaped nucleus within the amoeba controls the growth and reproduction of the amoeba.

Diet: Amoebas eat algae, bacteria, plant cells, and microscopic protozoa and metazoa - some amoebas are parasites. They eat by surrounding tiny particles of food with pseudopods, forming a bubble-like food vacuole. The food vacuole digests the food. Wastes and excess water are transported outside the cell by contractile vacuoles.

Locomotion: Amoebas move by changing the shape of their body, forming pseudopods (temporary foot-like structures). The word pseudopod means "false foot."

Reproduction: Amoebas reproduce asexually by binary fission. A parent cell divides (the nucleus also divides in a process called fission) and produces two smaller copies of itself.

Classification: Eukaryota (organisms with nucleated cells), Kingdom Protista (flagellates, amoebae, algae, and parasitic protists), Phylum Protozoa (single-celled organisms), Class Sarcodina (having pseudopods).