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Question #46941
The Question
R.H. Whittaker included 'phylogenetic relationships' as a core criterion for his Five-Kingdom classification, heavily relying on structural and functional traits to infer evolutionary history. However, in a small, isolated population that has recently survived a severe evolutionary bottleneck, this classical approach may fail to determine its true phylogenetic position. Which of the following best explains this limitation and identifies the modern taxonomic solution?
Options
- A.
The bottleneck increases heterozygosity, leading to convergent evolution; this is resolved by assessing analogous structures.
- B.
Genetic drift drives rapid phenotypic divergence that does not correlate with the actual time of divergence; this is resolved by molecular phylogenetics using conserved sequences like 16S rRNA.
- C.
The founder effect induces adaptive radiation that perfectly mirrors standard phylogenetic branching; this is resolved by strict morphological cladistics.
- D.
Small populations are immune to allele frequency shifts, making morphological traits highly conserved; this is resolved by biochemical assays of secondary metabolites.
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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
Whittaker’s Criteria Hierarchy|Allele Frequency Drift|Phylogeny
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize Whittaker's criteria ('phylogenetic relationships') without realizing his phylogeny was primarily morphological.
The trap requires synthesizing Class 11 Taxonomy with Class 12 Evolution: recognizing that genetic drift in small populations uncouples morphological change from true genetic divergence, thereby necessitating molecular tools (like the rRNA sequencing used to establish the Three-Domain system) to uncover true cladistic relationships.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biological Classification - Class 11 |
| Concept | Whittaker’s Criteria Hierarchy |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |