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Question #46374
The Question
Which of the following statements regarding the circulatory physics and evolution of the four-chambered heart in vertebrates is INCORRECT?
Options
- A.
Aves and Mammalia maintain an obligate double circulation, ensuring no mixing of oxygenated and deoxygenated blood in the heart or major vessels.
- B.
Because crocodiles possess a completely septated four-chambered heart, their circulatory system strictly prevents any mixing of systemic and pulmonary blood, even during prolonged diving.
- C.
The complete functional separation of pulmonary and systemic circuits in birds and mammals represents a convergent evolutionary adaptation supporting endothermy.
- D.
In crocodilians, increased pulmonary vascular resistance during apnea induces a right-to-left shunt, diverting blood away from the lungs via the Foramen of Panizza.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Crocodilian_Heart|Foramen_of_Panizza|Endothermic_Metabolism
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students memorize the NCERT rule '4-chambered heart = strict double circulation with zero mixing' and blindly apply it to crocodiles.
The trap exploits this by ignoring the evolutionary 'bridge' physiology of crocodilians, where an extrapulmonary bypass (Foramen of Panizza) allows a physiological right-to-left shunt during apnea, defying the textbook mammalian model.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Body Fluids and Circulation - Class 11 |
| Concept | Double Circulation Physics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |