spirogyra . labeled educational green algae structure.

algae biology blanket cell charophyta chlorophyte chloroplast closeup cytoplasm diagram educational explanation fauna filamentous freshwater graphic green habitat illustration isolated labeled life marine membrane mermaids micro mucilage nature nucleus ocean organic peripheral plant plantae pyrenoid scheme silk spirogyra structure tresses underwater vacuole vector water weed zoology zygnemataceae zygnematale zygnematales zygnematophyceae