11. A relationship in which one organism benefits and the other is harmed is called
a. commensalism.
b. parasitism.
c. synergism.
d. antagonism.

12. The degree or extent of disease-evoking power that a microorganism has is referred to as
a. virulence.
b. strength.
c. resistance.
d. competence.

13. The virulence factors of bacteria include
a. size, adhesion, resistance, and mutation.

b. colonization, invasion, toxins, and adhesion.
c. toxins, evasion of body defenses, motility, and size.
d. colonization, chemotaxis, fermentation, and toxins.