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Question #47397
The Question
During the evolutionary transition of vertebrates to terrestrial habitats, the architecture of the rib cage and the mechanism of pulmonary ventilation underwent significant modifications. Read the following statements regarding these evolutionary adaptations and identify the INCORRECT statement:
Options
- A.
The transition from amphibians to amniotes involved a shift from positive-pressure buccal pumping to negative-pressure costal aspiration.
- B.
In mammals, the rib cage acts as a muscular pump where the contraction of external intercostal muscles lifts the ribs and sternum, decreasing intrapulmonary pressure.
- C.
Snakes possess a complete rib cage with a well-developed sternum, representing an evolutionary adaptation that maximizes both skeletal stability for undulatory locomotion and costal aspiration.
- D.
Frogs lack a true rib cage and their ribs do not participate in pulmonary ventilation, necessitating the use of the buccal cavity floor to force air into the lungs.
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
Thoracic_Vertebrae|Sternum|Tetrapod_Locomotion|Convergent_Evolution
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often assume that because snakes are advanced terrestrial amniotes with highly visible rib-based locomotion, they possess a 'complete' rib cage (ribs + sternum).
The trap exploits the failure to recognize the evolutionary loss of the sternum in snakes—a necessary trade-off for swallowing large prey and achieving extreme spinal flexibility, distinguishing their anatomy from the standard amniote costal aspiration model.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Locomotion and Movement - Class 11 |
| Concept | Rib Cage Architecture |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |