What kingdom does plankton belong to?

Many people assume that Plankton belongs to the kingdom Plankton, however the term Plankton refers to many species. Plankton actually falls under the kingdom Protista. For an organism to be a Protist, they must be Eukaryote and must not fall under the other Eukaryotic kingdoms such as Animalia, Plantae and Fungi. A Eukaryote is defined as a orgasm that is made up of one or more cells in which each cell contains one or more nucleui and membrane bound organelles. Bacteria are not considered a Eukaryote because they do not have nuclei or membrane bound organelles. On the other hand, Amoeba are Eukaryotes because they both have a nucleus and membrane bound organelles.