Question

Assertion (A): Lots of undesirable microorganisms thrive in polluted water.

Reason (R): Standing water becomes the breeding ground for mosquitoes, which cause diseases.

Options

• Both A and R are true, and R is the correct reason for A.

• Both A and R are true, but R is not the correct reason for A.

• A is true, and R is false.

• A is false, and R is true.

Answer 1

Both A and R are true, but R is not the correct reason for A.

Explanation:

A is true, polluted/contaminated water supports the growth of many disease‑causing microorganisms (bacteria, viruses, protozoa). R is also true, stagnant/standing water provides breeding sites for mosquitoes that transmit diseases (malaria, dengue, etc.). However, the mosquito breeding in standing water is not the reason microorganisms thrive in polluted water; those microorganisms multiply because of contamination (sewage, organic waste, nutrients, low oxygen, etc.), not because of mosquito breeding.