CHLAMYDOMONAS
	Chlamydomonas is a genus of unicellular green algae (Chlorophyta). These algae are found all over the world, in soil, fresh water, oceans, and even in snow on mountaintops. Algae in this genus have a cell wall, a chloroplast, an "eye" that perceives light, and two anterior flagella with which they can swim using a breast-stroke type motion. More than 500 different species of Chlamydomonas have been described, but most scientists work with only a few.
The most widely used laboratory species is Chlamydomonas reinhardtii. Cells of this species are haploid, and can grow on a simple medium of inorganic salts, using photosynthesis to provide energy. They can also grow in total darkness if acetate is provided as an alternative carbon source. When deprived of nitrogen, haploid cells of opposite mating types can fuse to form a diploid zygospore which forms a hard outer wall that protects it from adverse environmental conditions. When conditions improve the diploid zygote undergoes meiosis and releases four haploid cells that resume vegetative growth, completing the sexual life cycle .
	Chlamydomonas is used as a model system for research on many fundamental questions in cell and molecular biology: how do cells move? how do they respond to environmental stimuli such as light? how does photosynthesis work? how do cells recognize one another? how do they maintain size homeostasis? how are organellar genomes inherited, and more . . . For more details, follow the links in the at the top right.