Which organelle is responsible for producing ATP through cellular respiration?

Correct Answer: C

Rationale: Mitochondria produce ATP via cellular respiration.

Correct Answer: A

Rationale: Deuterium oxide (D2O) is a standard tracer for measuring total body water via dilution; women have less TBW (~50%) than men (~60%) due to higher fat content.

Correct Answer: C

Rationale: Lymphocytes (~20-40% of WBCs) transform into plasma cells to produce antibodies; thymectomy affects T cells minimally in adults.

Correct Answer: A

Rationale: Platelets are produced by megakaryocytes in bone marrow and lack nuclei; they outnumber WBCs (~150-450K vs. 4-11K per µL).

Correct Answer: C

Rationale: Hemolytic anemia stimulates erythropoiesis to replace lost RBCs; EPO also works in nephrectomized patients.