The elementary zoology curriculum begins with a look at the differences between vertebrates and invertebrates. It progresses to an introduction to the five classes of vertebrates and their skeletal structures. The external parts of the vertebrates are presented with nomenclature; more in depth research is supported by the Animal Kingdom Charts and "first knowledge" questions. With these materials as a stepping off point, children explore how and where animals live, what they eat, their life cycles and physical characteristics. The system of scientific classification is formally introduced, and children learn that both vertebrates and invertebrates can be classified using this system. The nomenclature for the major phyla of invertebrates is then presented, and students do independent research on these animals. The study of invertebrates parallels their introduction to the Time Line of Life in history, since our earliest fossil record of life on Earth is that of invertebrate forms. The Animal Kingdom Charts and "first knowledge" questions also supplement invertebrate work.
The children then return to the vertebrates, looking at the internal parts of five classes. They expand their research projects to include scientific classification as well as information on the circulation, respiration, skin type, skeletal structure, reproduction, method of movement, nutritional needs and habitat of the animal they are researching. This study of the five classes of vertebrates also parallels Time Line of Life studies, as these classes are presented in the order in which fossil evidence shows that they appeared on Earth.