Flagellates are unicellular organisms whose movement organoids are long outgrowths, called flagella. The number of flagella in different species is different – from one to several hundred. Most flagellates have a permanent body shape, since it is covered with a thin and elastic membrane – the pellicle.
Pellicle is the outer dense layer of the cytoplasm, which ensures the preservation of a constant cell shape.
Euglena green is common in freshwater reservoirs. In the front of its cell there is one flagellum, and near the flagellum are located: a contractile vacuole, which removes excess water from the body, and a bright red light-sensitive eye – stigma, which perceives changes in illumination.
Stigma is a light-sensitive eye, capable of detecting the source of light.
The nucleus is located closer to the back of the cell.
The cytoplasm of euglena contains chloroplasts filled with chlorophyll. This ensures its ability to photosynthesize.
Euglena is able to change her dietary habits depending on environmental conditions. In the light, it eats autotrophically, and in the dark – heterotrophic (it eats particles of organic matter, small animals, unicellular algae). This type of food is called mixotrophic (mixed).
Through the contractile vacuole, harmful substances (decomposition products) and excess water are removed to the outside.
Euglena breathes oxygen dissolved in water. Gas exchange occurs, like in the amoeba, through the entire surface of the body.
Euglena green multiplies by longitudinal division in two.