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Question #46885
The Question
A researcher applies a metabolic inhibitor that specifically blocks the primary ATP-driven cation pumps in the excretory structures of both Periplaneta americana (Malpighian tubules) and Homo sapiens (Proximal Convoluted Tubule). Which of the following represents the most accurate physiological consequence of this dual inhibition?
Options
- A.
The cockroach will fail to secrete potassium urate into the tubule lumen, halting the water flux needed for hindgut conservation, while the human will suffer from severe glycosuria and electrolyte depletion due to the loss of the sodium gradient.
- B.
The cockroach will excrete copious amounts of dilute urine due to the failure of the rectal papillae, while the human will experience anuria due to the cessation of ultrafiltration in the Malpighian corpuscle.
- C.
Both organisms will immediately shift to ammonotelism, as the ATP-dependent synthesis of uric acid and urea occurs directly within these respective tubular structures.
- D.
The cockroach will accumulate uric acid in the hemolymph but maintain water balance, while the human will compensate for PCT failure by actively reabsorbing all filtered glucose in the Distal Convoluted Tubule.
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
Malpighian Tubules|Proximal Convoluted Tubule Selectivity|RAAS Pathway Feedback Loop
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students must distinguish between the driving forces of primary secretion and reabsorption.
A common misconception is that ultrafiltration in humans requires local ATP, or that insect excretion is purely passive.
Furthermore, it tests the strict anatomical localization of secondary active transport (glucose in PCT, not DCT) and nitrogenous waste synthesis (liver/fat body vs. tubules).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Structural Organisation in Animals - Class 11 |
| Concept | Cockroach Excretory Malpighian Tubules |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |