euglena syructure hand drawn

euglena biology cell organism science illustration structure nucleus diagram microorganism animal vector microbiology flagellum green vacuole micro unicellular chloroplast zoology stigma anatomy microscopy eyespot biological cellular laboratory education microscope protozoa membrane microbe protist study protozoan cytoplasm photosynthesis educational viridis plankton bacteria algae contractile mitochondria eukaryote nucleolus medical scientific scheme