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Question #47443
The Question
A patient is diagnosed with a targeted demyelinating disorder affecting the optic nerve. Despite normal functioning of the phototransduction cascade, the patient experiences severe visual impairment. Based on the neural circuitry of the retina, which of the following accurately explains the exact point of physiological failure?
Options
- A.
The hyperpolarization of rods and cones fails to trigger neurotransmitter release, arresting the signal at the first synapse.
- B.
Graded potentials in the bipolar cells fail to reach the threshold required to initiate saltatory conduction.
- C.
Action potentials generated by the retinal ganglion cells undergo rapid current leak and fail to propagate to the lateral geniculate nucleus.
- D.
The unmyelinated axons of the photoreceptors fail to generate the action potentials required for optic nerve transmission.
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
Ganglion_Cells|Optic_Nerve|Nodes_of_Ranvier
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between graded potentials and action potentials in the retinal circuitry.
A common misconception is that photoreceptors or bipolar cells fire action potentials.
Students must recall the specific NCERT line stating that action potentials are generated in the ganglion cells.
Furthermore, they must link the optic nerve to ganglion cell axons and understand that demyelination specifically disrupts saltatory conduction of action potentials, not the initial biochemical phototransduction cascade.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Neural Control and Coordination - Class 11 |
| Concept | Retina Phototransduction Cascade |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |