Let me share with you a difference between brown algae,red algae and green algae.
| Aspect | Brown Algae | Red Algae | Green Algae |
| Appearance | Brown | Red | Green |
| Type of pigment | Fucoxanthin | Phycoerythrin | Chlorophylls a and b |
| Cellular organizations | Mostly multicellular and some are unicellular | Mostly multicellular | Both unicellular and multicellular forms |
| Composition of cell wall | Cellulose with additional alginates and other polysaccharides | Cellulose with additional polysaccharides | Cellulose with additional polysaccharides |
| Storage product | Laminarin | Floridean starch | Starch and other carbohydrates |
| Type of reproduction | Alternation of generations, with a dominant sporophyte phase | Alternation of generations, with a dominant gametophyte phase | Varied – includes sexual and asexual reproduction, depending on the species |
| Habitat | Marine | Marine | Diverse habitats – marine, freshwater and terrestrial environments |
| Economic importance | Source of alginates used in food, pharmaceuticals and industry | Used in food (e.g., nori), cosmetics and as thickeners | Various uses, including as food (e.g., spirulina), biofuels and as research models |
| Cellulose arrangement | Typically arranged in a haphazard pattern | Cellulose fibers are typically arranged in a well-defined pattern | Variable arrangements depending on the species |
| Examples | · Laminaria · Fucus · Sargassum | · Porphyra · Gelidium · Corallina | · Chlamydomonas · Spirogyra · Ulva |