Question

Pathogens are harmful to mankind
Reason: They either kill or prevent the growth of microorganisms
A) Both assertion and reason are correct, and reason is the correct explanation for assertion
B) Both assertion and reason are correct, but reason is not the correct explanation for assertion
C) Assertion is correct, reason is incorrect
D) Both assertion and reason are incorrect

Answer 1

Hint: Disease causing organisms are said to be pathogenic. Not all bacteria are pathogenic; many of them are beneficial to us, like the lactobacilli that live in our digestive tracts. Imbalances may cause problems with our health.

Complete Answer:
- The assertion is correct, but the reason is not the correct explanation for the assertion at all. These activities may or may not be directly related to pathogenicity. Option A is incorrect.
- The assertion is correct, as pathogens are disease causing organisms whether they are microbes or parasites. However, the reason is incorrect. Pathogenic organisms may kill or prevent the growth of microorganisms, but that is not necessarily what they do, and it may not even be related to their pathogenic effects on mankind. Option B is not correct.
- The assertion is correct and the reason is incorrect. Pathogenic organisms are harmful because they directly affect the way our bodies function. They may destroy cells, prevent us from getting any nutrition like the tapeworm does, cause debilitating responses, or even cause us to attack our own tissues as the increased response in TB does. Option C is the correct answer.
- Option D is incorrect because the assertion is correct.

Hence the correct answer is option C.

Note: There are instances in which pathogens destroy our normal body flora or change the pH or moisture levels hindering the growth of beneficial microorganisms. An increasing cause for worry however, is that overuse and incorrect administration of antibiotics is creating multi-drug resistant pathogens. Multi-drug resistant S. aureus is a particular problematic example.