The ability of a microorganism to produce a toxin is called _____.

• A. Infectivity
• B. Virulence
• C. Invasiveness
• D. Toxigenicity

Answer: (D)

Toxigenicity is the ability of a microorganism to produce toxins that damage host tissues. Infectivity means the capacity to establish infection, and invasiveness refers to the organism’s ability to spread into and through tissues. Virulence is the overall capacity to cause disease, which can involve toxins, invasion, and other factors. The question focuses specifically on toxin production, so toxigenicity is the precise term. For example, Corynebacterium diphtheriae causes disease largely through its toxin, illustrating how toxin production drives disease. Some pathogens cause disease mainly through invasion rather than toxins, but the term for toxin production remains toxigenicity.