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Question #46763
The Question
A human spermatozoon exhibits complete immotility due to a dual cellular defect: a structural failure in the basal body and a bioenergetic failure in the mitochondria. Regarding the normal ultrastructure and evolutionary origin of these organelles, which of the following statements is INCORRECT?
Options
- A.
The basal body, from which the flagellum emerges, is a centriole-like structure that shares the 9+2 microtubular doublet arrangement of the axoneme.
- B.
The bioenergetic failure occurs in a semi-autonomous organelle that divides by fission and contains 70S ribosomes, reflecting its prokaryotic endosymbiotic origin.
- C.
In a normal flagellum, the central pair of microtubules is enclosed by a central sheath, which connects to one tubule of each peripheral doublet via nine radial spokes.
- D.
The ATP required for motility is generated by an organelle whose inner membrane forms infoldings called cristae towards the matrix to increase surface area.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Cilia and Flagella Ultrastructure|Mitochondrial Endosymbiotic Evidence|Terminal Electron Acceptor
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Microtubular Architecture Transition.
Students frequently assume that because the flagellum emerges directly from the basal body, both structures share the exact same internal architecture.
The trap relies on failing to distinguish between the 9+2 doublet arrangement of the functional axoneme and the 9+0 triplet arrangement of its centriolar anchor (the basal body).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell – The Unit of Life - Class 11 |
| Concept | Cilia and Flagella Ultrastructure |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |