- A Only once per circuit, directly to the body
- B Twice per circuit (to lungs AND to body)
- C In two directions at the same simultaneous moment
- D As many as four separate times per single circuit
Correct answer: B. Twice per circuit (to lungs AND to body)
Explanation: Humans have double circulation: pulmonary (heart to lungs and back) and systemic (heart to body and back). Blood passes through the heart twice per circuit.
Concept context
Blood, lymph, the heart, the cardiac cycle, blood pressure, and ECG. High NEET weightage.