Protista Kingdom of Eukaryotes. The kingdom Protista contains the single-celled eukaryotes in contrast to the bacteria which are examples of the prokaryotic cell type. Protists are a diverse group of organisms that are either unicellular or multicellular without highly specialized tissues. They could be viewed as those eukaryotes that cannot be classified as one of the other cell types. They include the one-celled animal-like protozoa, one-celled algae, slime molds and water molds.