This study guide covers the key structures, reproductive systems, digestive systems, levels of organization, and ecological roles of diatoms, dinoflagellates, foraminiferans, Euglena, and Volvox. It includes diagrams of representative organisms and definitions of important terms. Short answer questions ask the student to compare and contrast diatoms, dinoflagellates, and forams, and describe the food capture methods of foraminiferans.