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Question #47382
The Question
Mammals in cold climates typically adhere to Allen’s Rule to minimize heat loss and rely on shivering thermogenesis mediated by specific skeletal muscle fibers. If a small mammal with a high surface-area-to-volume ratio (violating Allen's Rule) is forced to adapt to a prolonged cold environment, what compensatory eco-physiological shift in its skeletal muscles is most likely to occur to avoid bioenergetic exhaustion?
Options
- A.
A shift towards fast-twitch, glycolytic fiber dominance to conserve the high metabolic energy otherwise required to maintain dense oxidative mitochondria.
- B.
A proportional increase in slow-twitch, myoglobin-rich fibers to sustain continuous shivering thermogenesis despite the rapid heat loss.
- C.
Enhanced vascularization and increased mitochondrial density in white muscle fibers to facilitate aerobic glycolysis.
- D.
Hypertrophy of the sarcoplasmic reticulum in red muscle fibers to increase myoglobin-mediated oxygen storage.
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
Thermoregulation|Metabolic_Rate|Red_Fiber_Density
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students reflexively link 'cold climates' to 'red muscle fibers' due to shivering thermogenesis.
The trap is failing to recognize the bioenergetic limits of this adaptation.
When anatomical constraints (Allen's Rule) are violated, the metabolic cost of maintaining oxidative mitochondria becomes a liability, forcing an evolutionary trade-off towards energy-conserving white fibers.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Locomotion and Movement - Class 11 |
| Concept | Red vs. White Muscle Fibers |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |