Ключевые слова: algae, animal, aquatic, background, biology, cell, cilia, disease, education, etching, eukaryotic, fauna, flora, food, food vacuole, freshwater, green, green algae, invisible, lab, laboratory, life, macro, marine, micrasterias, micro, microbiology, microorganism, microscope, microscopic, microscopy, nature, nucleus, organism, paramecium, pediastrum, phytoplankton, plankton, pond, protist, protista, protozoa, protozoan, protozoans, research, science, scientific, species, spirostomum, spirostomum intermedium, under, vorticella, waste, water, xanthidium, zoology,