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Question #46174
The Question
Evaluate the energetic trade-offs between the jawless Cyclostomata and the jawed Chondrichthyes. Which of the following statements is INCORRECT regarding their ecological fitness and anatomical adaptations?
Options
- A.
Cyclostomes utilize a sucking, circular mouth devoid of jaws, which serves as an energetically efficient adaptation for an ectoparasitic niche on host fishes.
- B.
The teeth of Chondrichthyes are backwardly directed modified placoid scales that, along with powerful jaws, support a predaceous lifestyle requiring high metabolic investment.
- C.
The evolutionary development of jaws in Chondrichthyes universally confers higher ecological fitness by reducing the overall metabolic energy expenditure required for feeding compared to Cyclostomes.
- D.
Due to the absence of an air bladder, Chondrichthyes must expend continuous muscular energy to avoid sinking, whereas adult Cyclostomes can mitigate such locomotor costs by anchoring to hosts.
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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
Cyclostomata Dentition|Ecological Fitness|Chondrichthyes vs Osteichthyes Buoyancy
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: The 'Teleological Fallacy' in evolution.
Students often assume that morphologically 'advanced' traits (like jaws in Gnathostomata) automatically equate to higher energetic efficiency or universal ecological fitness.
This question forces students to synthesize NCERT morphological facts (lack of air bladder, placoid teeth, sucking mouth) with the concept of metabolic trade-offs, realizing that the 'primitive' Cyclostome ectoparasitic model is actually highly energy-efficient.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Cyclostomata Dentition |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |