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Question #47431
The Question
Mycoplasma species are unique monerans that completely lack a rigid cell wall, allowing their highly flexible cell membranes to intimately interact with host tissues. Suppose a pathogenic Mycoplasma strain colonizes the synaptic cleft of a human chemical synapse and secretes a potent chelator that completely depletes Ca^{2+} ions from the local extracellular fluid. Which of the following statements is INCORRECT regarding the immediate physiological consequences of this infection?
Options
- A.
The arrival of an action potential at the presynaptic terminal will fail to open the voltage-gated Ca^{2+} channels.
- B.
The movement and fusion of synaptic vesicles with the presynaptic membrane will be completely halted.
- C.
The depolarization wave traveling down the presynaptic axon will remain unaffected by the Ca^{2+} depletion.
- D.
The release of neurotransmitters via exocytosis into the synaptic cleft will not occur.
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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
Calcium_Signaling|Synaptotagmin|Synaptic_Vesicle
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between the 'gating mechanism' of an ion channel (which is voltage-dependent) and the 'driving force' for ion movement (which is concentration-dependent).
Students often fall into the trap of assuming that if an ion is absent from the extracellular fluid, the channel itself fails to open.
This question integrates the NCERT structural feature of Mycoplasma (lack of a cell wall enabling intimate cleft colonization) with the precise sequence of events in chemical synaptic transmission.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Neural Control and Coordination - Class 11 |
| Concept | Synaptic Vesicle Exocytosis Trigger |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |