Human Health And Disease

Step 1: Understanding the causative organisms.
- Syphilis is caused by Treponema pallidum (P-3).

- Bacillary dysentery is caused by Shigella dysenteriae (Q-1).

- Gas gangrene is caused by Clostridium perfringens (R-4).

- Whooping cough is caused by Bordetella pertussis (S-2).

Step 2: Analyzing the options.
(A) P-2, Q-1, R-4, S-3: Incorrect — Syphilis is caused by Treponema pallidum, not Shigella.
(B) P-4, Q-3, R-1, S-2: Incorrect — The pairing of syphilis with Clostridium is incorrect.
(C) P-2, Q-3, R-1, S-4: Incorrect — The pairings are incorrect.
(D) P-3, Q-1, R-4, S-2: Correct — This correctly matches the diseases with their causative organisms.

Step 3: Conclusion.
The correct answer is (D) P-3, Q-1, R-4, S-2.

To solve this question, we need to correctly match the microorganisms listed in Group I with the diseases listed in Group II.

1. Treponema pallidum: This bacterium is known to cause syphilis, which is a sexually transmitted infection. Thus, match P with 4.
2. Trypanosoma cruzi: This is a protozoan parasite that causes Chagas disease, primarily in Latin America. Thus, match Q with 3.
3. Trypanosoma gambiense: This species is one of the causative agents of sleeping sickness (African trypanosomiasis) transmitted by the tsetse fly. Thus, match R with 1.
4. Bordetella pertussis: This bacterium causes whooping cough (pertussis), which is a highly contagious respiratory disease. Thus, match S with 2.

Based on the above analysis, the correct matches are:

Therefore, the correct answer is: P-4, Q-3, R-1, S-2.