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Question #46972
The Question
Organisms exhibit distinct signaling mechanisms to counter physiological or environmental stress, such as the activation of the Renin-Angiotensin-Aldosterone System (RAAS) in humans during hypovolemia, and the aggregation of slime molds during nutrient starvation. Which of the following statements regarding these stress responses is INCORRECT?
Options
- A.
RAAS is initiated by a drop in glomerular filtration rate, whereas slime mold aggregation is an adaptive response to environmental nutrient depletion.
- B.
RAAS operates via systemic endocrine signaling through the bloodstream, whereas slime mold aggregation relies on the local environmental diffusion of chemoattractants like cyclic AMP.
- C.
Both stress-response mechanisms rely entirely on chemical messengers that bind to specific cell-surface receptors to alter target cell activity.
- D.
The RAAS cascade culminates in the reabsorption of Na+ and water to restore blood volume, while slime mold aggregation ultimately leads to the formation of spore-bearing fruiting bodies.
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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
Pteridophyte Heterospory Evolution|Polyembryony Mechanisms|Slime Mold Aggregation
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating 'Mechanism of Hormone Action' with 'Excretory System' and 'Biological Classification'.
Students often generalize that all signaling molecules in a cascade bind to surface receptors.
The trap exploits the failure to recognize Aldosterone as a steroid hormone that requires an intracellular receptor, contrasting it with the surface-receptor binding of cAMP in slime molds and Angiotensin II in RAAS.
Even if the student is unfamiliar with the exact receptor for slime mold cAMP, core NCERT knowledge of Aldosterone's intracellular nature makes C definitively false.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biological Classification - Class 11 |
| Concept | Slime Mold Aggregation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |