Before You Begin
Question #46115
The Question
In the context of physiological ecology and animal classification, diploblastic organisms such as Adamsia and Pleurobrachia are strict environmental conformers. Which of the following structural constraints fundamentally prevents them from achieving endothermy?
Options
- A.
The presence of an undifferentiated mesoglea, which acts as a highly efficient thermal conductor, preventing the retention of metabolic heat.
- B.
The absence of a mesoderm, which precludes the development of the complex muscular and circulatory systems required for high metabolic heat generation and distribution.
- C.
Their cellular level of organization, which restricts the formation of a true coelom necessary to accommodate high-energy organ systems.
- D.
The reliance on a gastrovascular cavity for both digestion and circulation, which inherently maximizes their surface area-to-volume ratio, causing rapid heat loss.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Thermoregulation logic|Cnidaria|Ectothermy
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating 'Animal Kingdom' (germ layers and organ system origins) with 'Organisms and Populations' (conformers vs. regulators).
The trap lies in Option C, which uses a plausible-sounding physiological constraint (lack of coelom) but pairs it with a fatal taxonomic error ('cellular level of organization' instead of 'tissue level').
Students must synthesize anatomical limitations (lack of mesoderm) with physiological consequences (inability to thermoregulate).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Diploblastic Exception |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |