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Question #46172
The Question
During the metamorphosis of a cyclostome (e.g., Petromyzon), a researcher applies a highly specific chemical inhibitor that completely arrests the cell cycle at the G1/S checkpoint in the developing odontogenic epithelium of the oral disc. Which of the following accurately describes the immediate cytological consequence and the ultimate physiological outcome for this organism?
Options
- A.
Centriole duplication in the cytoplasm is prevented; the organism fails to develop keratinized teeth, rendering it unable to sustain its ectoparasitic lifestyle.
- B.
Centriole duplication in the nucleus is halted; the organism fails to develop calcareous teeth, leading to starvation.
- C.
DNA replication proceeds but centriole duplication in the G2 phase is arrested; the circular mouth fails to develop functional jaws.
- D.
Spindle apparatus assembly is directly inhibited in the G1 phase; the organism develops a sucking mouth but lacks a cartilaginous cranium.
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
Cyclostomata Dentition|Centriole Duplication Timing|Cell Cycle
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: This question tests cross-chapter synthesis between 'Cell Cycle and Cell Division' and 'Animal Kingdom'.
The primary trap is the exact timing and location of centriole duplication (S phase, cytoplasm) versus DNA replication (S phase, nucleus).
Students often confuse the location of centriole duplication or mistakenly attribute jaw/calcareous teeth development to jawless, keratin-toothed cyclostomes.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Cyclostomata Dentition |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |