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Question #46163
The Question
The post-anal tail is a hallmark feature of Phylum Chordata. When analyzing the evolutionary adaptations of Arctic mammals (e.g., Arctic fox) through the lens of ecogeographical principles, which of the following statements correctly describes the modification of this trait?
Options
- A.
The tail is morphologically reduced to decrease the organism's overall surface-to-volume ratio, thereby minimizing heat dissipation in accordance with Allen's Rule.
- B.
The tail is elongated to accommodate a thicker layer of subcutaneous blubber, increasing the surface-to-volume ratio as per Bergmann's Rule.
- C.
The tail is entirely absent during embryonic development to conserve metabolic energy, representing a unique exception to the chordate body plan.
- D.
The tail retains its ancestral length but exhibits increased peripheral vasodilation to maintain core body temperature via Allen's Rule.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Chordata|Allen’s_Rule|Surface-to-Volume_Ratio
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: This question requires the synthesis of two distinct NCERT chapters: 'Animal Kingdom' (Chordate defining features) and 'Organisms and Populations' (Allen's Rule).
Students often memorize Allen's Rule strictly as 'short ears and limbs' without recognizing that the tail is also a protruding appendage derived from the fundamental chordate post-anal tail, and is thus subject to the exact same thermoregulatory selection pressures (minimizing the SA:V ratio).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Chordata Fundamental Trio |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |