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Question #45725
The Question
Uricotelic organisms excrete nitrogenous waste as a paste or pellet with minimum water loss. If a hypothetical genetic mutation in an avian species causes the ectopic hyperactivation of a mammalian-like Renin-Angiotensin-Aldosterone System (RAAS), which of the following would be the most likely physiological fallout?
Options
- A.
Increased Glomerular Filtration Rate (GFR) leading to the efficient flushing of highly soluble uric acid into the cloaca.
- B.
Severe obstructive uropathy due to the premature precipitation of uric acid crystals in the renal tubules.
- C.
A compensatory metabolic shift in the liver from uric acid synthesis to the ornithine cycle to prevent renal toxicity.
- D.
Enhanced conservation of water without adverse effects, as the RAAS pathway synergizes perfectly with uricotelic adaptations.
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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
Uricotelic|Ureotelic|Renin-Angiotensin|Aquaporins
Why This Question Is Tricky
Common Mistakes
The Conceptual Pivot lies in understanding the physical chemistry of nitrogenous wastes versus hormonal osmoregulation.
Students often memorize RAAS simply as a 'water-saving' mechanism and might assume it would benefit a water-conserving uricotelic organism (Option D trap).
The synthesis requires realizing that while mammals excrete highly soluble urea (which can handle massive water reabsorption), birds excrete insoluble uric acid.
Applying mammalian-level distal water reabsorption to a uricotelic system turns a biological advantage into a fatal physical obstruction.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Excretory Products and Their Elimination - Class 11 |
| Concept | RAAS Pathway Feedback Loop |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |