( a ) photosynthetic autotrophs - have chlorophyll a and b similar to green plants, multicellular, colonial, freshwater/marine or terrestrial algae, gelatinous sheath surrounding the colonies, often form blooms in polluted water bodies, can fix atmospheric nitrogen in specialised cells called heterocysts
( b ) photosynthetic autotrophs - have chlorophyll a and b similar to green plants, unicellular, colonial or filamentous, freshwater/marine or terrestrial algae, gelatinous sheath surrounding the colonies, can fix atmospheric nitrogen in specialised cells called heterocysts
( c ) photosynthetic autotrophs - have chlorophyll b similar to green plants, unicellular, colonial never filamentous, freshwater/marine or terrestrial algae, gelatinous sheath surrounding the colonies, often form blooms in polluted water bodies, can fix atmospheric nitrogen in specialised cells called heterocysts
( d ) photosynthetic autotrophs - have chlorophyll a, , unicellular, colonial or filamentous, freshwater/marine or terrestrial algae, gelatinous sheath surrounding the colonies, can fix atmospheric nitrogen in heterocysts
