question_answer 53)

  Becoming exposed to or infected with an infectious microbe does not necessarily mean developing noticeable disease. Explain.

Answer:

  The strong immune system of a healthy person normally fights of microbes. The body has specialized cells to kill the pathogenic microbes. These cells are active when infectious microbes enter the body and if they are successful in removing the pathogen, we remain disease-free. So, even exposure to infectious microbes may not cause disease to a person having strong immune system. (Also refer to Q. 33)