Chlamydomonas

it is oval or sperical in shape and bounded by a cell wall containing hemi-cellulose. At the anterior end, the wall projects and thickens to form a colourless papilla. It has two flagella which are used for locomotion. There is the contractile vacuole for osmoregulation. It posses a nucleus and a cup shaped chloroplast which contains chlorophyll. It has a pyrenoid which is used for production of starch. A red eye spot is embedded on the anterior border of the chloroplast which responds to light stimulus