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Question #45771
The Question
A 28-year-old male presents with a triad of chronic bronchitis, infertility due to immotile spermatozoa, and situs inversus (transposition of visceral organs). At the cellular level, this condition is primarily caused by a genetic defect in the ultrastructure of cilia and flagella. Which of the following correctly identifies the defective component and its specific function in a normal eukaryotic axoneme?
Options
- A.
Absence of nexin links, which normally generate the ATP-dependent sliding force between adjacent microtubule doublets.
- B.
Mutation in the dynein arms attached to the peripheral microtubule doublets, abolishing the sliding microtubule mechanism.
- C.
Defect in the radial spokes, which normally connect the 9+0 peripheral triplets in the axoneme to the central sheath.
- D.
Absence of the central microtubule pair, preventing the formation of the basal body from the centriole.
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|Axoneme
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating micro-level ultrastructure (NCERT Class 11 'Cell: The Unit of Life') with macro-level systemic consequences.
The trap relies on students confusing the specific functional roles of axonemal components (Dynein for force generation vs.
Nexin for bending constraint) and mixing up the 9+2 axonemal arrangement with the 9+0 centriolar/basal body arrangement.
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 |