Chapter 1, Problem 3MCQ

Which of the following is the most important element of Koch’s germ theory of disease? The animal shows disease symptoms when

1. a. the animal has been in contact with a sick animal.
2. b. the animal has a lowered resistance.
3. c. a microorganism is observed in the animal.
4. d. a microorganism is inoculated into the animal.
5. e. microorganisms can be cultured from the animal.