This book introduces you to creatures from the protist kingdom, from microscopic protozoans to seaweedlike algae. It examines the parts, life cycle, and reproduction of various types of protists. It also looks at the harmful effects some protists have on humans. Did You Know? The deadly disease malaria is caused in part by the protist Plasmodium. The fossils of one type of protist, the red algae, date back more than 500 million years. Paramecium, a well known protist, uses hairlike cilia to sweep food into its mouth.