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Question #45772
The Question
Eukaryotic flagellar movement relies on the sliding of the 9+2 axonemal microtubules. If human spermatozoa are exposed to a respiratory poison like cyanide, intracellular ATP production ceases. Which of the following best explains the immediate mechanical consequence on the flagellum?
Options
- A.
The inter-doublet linkers (nexin) degrade without ATP, causing the doublets to slide past each other without generating a bending wave.
- B.
The ATPase-dependent dynein arms cannot detach and reattach to adjacent doublets, halting the sliding mechanism and leaving the flagellum rigid.
- C.
The radial spokes detach from the central sheath, disrupting the structural integrity of the 9+2 arrangement and causing axonemal collapse.
- D.
The peripheral microtubule doublets rapidly depolymerize into tubulin monomers due to the lack of ATP-driven capping.
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
Dynein_ATPase|Microtubule_doublets|Nexin_link
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between the ATP-dependent motor proteins (dynein) and the ATP-independent structural/constraining proteins (inter-doublet linkers/nexin and radial spokes).
A common misconception is that ATP depletion causes structural depolymerization of the axoneme, whereas it actually causes mechanical paralysis (a rigor state) because the motor proteins cannot cycle.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Locomotion and Movement - Class 11 |
| Concept | Ciliary/Flagellar Ultrastructure |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |