Protozoa

Proteists (Protozoa, protozoa) are one of the large types of the animal kingdom. The processes of excretion, respiration, and blood circulation in these organisms are poorly represented. The sizes of protozoa range from 7 to 40 microns. The cells are round or oval in shape, closely adjacent to each other, forming entire colonies. As a rule, in protozoa the cells are not always homogeneous. A small number of organelles, and sometimes their absence, is determined by one layer of cells, which is delimited from the cytoplasm. Protozoa are classified as lower eukaryotes. The organization is based on the principle of the contractile vacuole. Contractile vacu