Q 1. Fill in the blanks with the correct vocabulary term. a. ______Infectivity___________ = successful invasion of the body by a pathogenic microorganism b. _________________ _____________________ = enzymes, toxins, and other factors that affect the relative ability of a pathogen to infect and cause disease c. _________________ _______________________ ___________________ = living or nonliving continuous source of infectious disease d. ________________ ________________ = is the stage in the infectious disease process where there is a short stage of generalized, mild symptoms that precedes illness.