Green algae. Coloured scanning electron micrograph (SEM) of two Chlamydomonas sp. green algae. These single-celled organisms are aquatic, living in freshwater habitats. They use their two, tail- like flagella for swimming. These algae are also photosynthetic; they contain two types of the pigment chlorophyll, which they use to capture sunlight energy for the manufacture of sugars. Magnification: x1770 at 6x7cm size.