Chlorophyceae (Green Algae)

Chlorophyceae, the green algae, are named for the dominance of chlorophyll a and b in their chloroplasts, which gives them their characteristic green colour.

Habitat. They are mostly freshwater organisms, with only a few forms found in brackish or marine water.

Body form. The plant body may be unicellular, colonial, or filamentous.

Cell wall and chloroplast. The cell wall is made of cellulose. Chloroplasts show a striking variety of shapes across different genera — discoid, plate-like, reticulate (net-like), cup-shaped, ribbon-shaped, or spiral — but all contain chlorophyll a and b. Small proteinaceous bodies called pyrenoids, associated with starch synthesis and storage, sit within the chloroplast.

Stored food. Food is stored as true starch. …