Answer: Salmonella typhi.
- A Salmonella typhi
- B Vibrio cholerae
- C Entamoeba histolytica
- D Plasmodium vivax
Correct answer: A. Salmonella typhi
Explanation: Typhoid fever is caused by Salmonella typhi, a gram-negative bacterium. It spreads through contaminated food and water. Diagnosis: Widal test. Treatment: antibiotics (ciprofloxacin, azithromycin).
The Plasmodium parasite needs both hosts: the female Anopheles mosquito injects sporozoites while biting (infecting the human liver and RBCs, causing the malaria fever cycle), then picks up gametocytes from an infected person's blood, completing the parasite's sexual stage inside the mosquito.
Concept context
Pathogens, infectious diseases, non-infectious diseases, drugs, cancer, and public health. High NEET importance.