This document outlines Chapter 20 on protists. It discusses the three main groups of protists - animal-like protists (protozoa), plant-like protists (algae), and fungus-like protists. For animal-like protists, it describes different phyla including zooflagellates, sarcodines, ciliates and sporozoans. It also discusses how some protists can cause diseases like malaria. For plant-like protists, it outlines different types of algae and their pigments. Plant-like protists are important as the base of aquatic food chains. Fungus-like protists obtain nutrients externally and include water molds and slime molds, serving important ecological