The respiratory centre is located in the

Correct Answer: C

Rationale: The respiratory center, controlling breathing, is in the medulla oblongata. 'Medulla oblongata,' is correct, per physiology (e.g., Costanzo), with rhythm and depth regulation. 'Cerebrum,' handles cognition. 'Cerebellum,' coordinates movement. 'Hypothalamus,' regulates homeostasis, not breathing directly. The medulla's role makes C the accurate answer.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: C

Rationale: Pathogenic bacteria cause disease. 'Lactobacillus,' is correct as the exception, typically beneficial (e.g., gut flora), per microbiology (e.g., Brock). 'Salmonella,' causes food poisoning. 'Shigella,' causes dysentery. 'Clostridium,' includes pathogens like C. tetani. Lactobacillus' probiotic role makes C the accurate answer.

Correct Answer: D

Rationale: Antibiotics disrupt bacterial processes. 'Pain relief,' is correct as the exception, not an antibiotic mechanism, per pharmacology (e.g., Walsh). 'Cell wall synthesis inhibition,' (e.g., penicillin) weakens bacteria. 'Protein synthesis inhibition,' (e.g., tetracycline) halts growth. 'Nucleic acid synthesis inhibition,' (e.g., quinolones) stops replication. Pain relief's irrelevance makes D the precise answer.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.