Sun -> Primary Producers -> Primary Consumers -> Secondary Consumers -> Tertiary Consumers. Primary consumers, which is more or less synonymous with herbivores, eat the things that turn sunlight into energy. Secondary consumers are carnivores who eat the primary consumers. Tertiary consumers are at the top, eating all the secondary consumers and primary consumers that they can. A rabbit would be an example of a primary consumer. The fox that eats the rabbit is an example of a secondary consumer. Wolves are tertiary consumers, because they come along and eat everybody involved, and because nobody eats them.
Typically a master's degree in exercise physiology is required, but you may only need an undergraduate degree in physical education, exercise science, health science or nutrition to work for a community organization.
Diplomates of the ABP are ethically required to have a practice limited to prosthodontics. Fellows of the American College of Prosthodontists (FACP) are required to have a dental degree, have completed three years of prosthodontic speciality training, and be board certified by the ABP.