Question: what is the difference between algae and euglena?
Answer: Euglena is entirely unicellular, has no collagen and no cellulose, stores energy in paramylon bodies (not starch as plants do). Euglena is photosynthetic, but the origin of Euglena's chloroplasts is taken *from* a green alga, not directly from cyanobacteria/chloroxybacteria as plants and green algae are.