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Question #46927
The Question
Classical taxonomy utilizes rigid hierarchical ranks based on vertical descent. However, when classifying certain eubacteria, taxonomists find that while their mesosome geometry suggests one specific lineage, their plasmid 'Ori' (Origin of replication) sequences suggest a completely different, distant lineage. Which of the following best explains this taxonomic conflict and the failure of the Biological Species Concept in this scenario?
Options
- A.
Extensive lateral gene transfer of plasmids violates the vertical descent model, creating reticulate phylogenies that blur species boundaries.
- B.
The 'Ori' sequence is highly conserved across all Monerans, making it an insufficient analytical tool for distinguishing between closely related strains.
- C.
Mesosomes are analogous structures formed by convergent evolution, rendering morphological classification in prokaryotes entirely invalid.
- D.
Eubacteria exhibit obligate sexual reproduction, which constantly reshuffles the 'Ori' sequences during gametogenesis.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Key Analytical Nature|Prokaryotic Mesosome Geometry|Ori Sequence Stringency
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that phylogenetic classification (based on genetics) is the most advanced and accurate system.
However, they fail to realize that classical phylogeny assumes a branching tree (vertical descent), which is fundamentally disrupted by Horizontal Gene Transfer in prokaryotes.
The trap lies in assuming all genetic similarities in bacteria are due to common ancestry (homology), ignoring the massive role of lateral gene transfer in bacterial evolution.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | The Living World - Class 11 |
| Concept | Key Analytical Nature |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |