Like algae and plants, Euglena cells contain chloroplasts that allow them to create food through photosynthesis, but they can also take in nutrients from other organisms when light is not available. Euglena are a unique group of single-cell organisms that have some of the same functions as both plants and animals.
Scientists have long debated whether Euglena should be classified as plants or animals, but they are usually listed as part of the Protist kingdom along with paramecium, amoeba and other microscopic organisms. The genus Euglena contains numerous different species that share many similar characteristics.
Euglena usually live in puddles, small ponds and other calm waters and can propel themselves through the water by means of a thin whip-like tail known as a flagellum. The flagellum, which is black, is on the front of the Euglena and spins through the water to pull the cell forward. All species of Euglena have a red eye-like spot in the cell that helps it detect the sunlight it needs for photosynthesis. Euglena reproduce by splitting the cell in two (fission), which results in two identical organisms. During this process, one of the halves keeps the flagellum, while the other grows a new one.