Final answer:
Pathogenesis is the study of the sequence of events that occur in a disease, involving steps such as exposure, adhesion, invasion, and infection.
Step-by-step explanation:
Pathogenesis is the study of the sequence of events that occur in a disease. To cause disease, a pathogen must successfully achieve four steps or stages of pathogenesis: exposure (contact), adhesion (colonization), invasion, and infection. The pathogen must be able to gain entry to the host, travel to the location where it can establish an infection, evade or overcome the host's immune response, and cause damage (i.e., disease) to the host.