This biologic kingdom is composed of eukaryotic organisms: unicellular and multicellular algae, slime molds, and unicellular or simple colonial protozoans. Protists obtain their nutrition via several methods, including photosynthesis, devouring other organisms, and absorption. Protists can reproduce sexually or asexually, and they can be sedentary or move with pseudopods, flagella, or cilia. There are over 55,000 known living species and over 35,000 known extinct species in this kingdom.