Coloured scanning electron micrograph (TEM) of Euglena gracilis cell pellicle and internal cytoplasmic organelles: golgi apparatus (light green and blue), chloroplast (green), mitochondria (dark pink), pyrenoid body (light yellow), ribosomes (brown), vacuole (light blue-green), nuclear membrane (purple), nucleus (dark brown), chromatin (orange). Euglena spp. can change their shape readily due to microtubules located beneath their cell membrane (pellicle, light orange). Euglena gracilis is a fresh water, flagellated protozoan often classified in a group called euglenoids. Euglena spp. normally contain chloroplasts but in prolonged darkness they become heterotrophic and engulf other small organisms. Magnification: x5, 505 when shortest axis printed at 25 millimetres. |