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Question #46937
The Question
R.H. Whittaker’s five-kingdom system classifies Archaebacteria under Kingdom Monera alongside Eubacteria. However, deep biochemical divergences exist between these two groups. Which of the following statements regarding their taxonomic placement and evolutionary adaptations is INCORRECT?
Options
- A.
Archaebacteria are placed in Kingdom Monera primarily due to their prokaryotic cellular organization, despite lacking the characteristic cell wall composition of true bacteria.
- B.
The survival of Archaebacteria in extreme thermal vents is facilitated by cell membranes containing branched-chain lipids with ether linkages.
- C.
The structural rigidity of the archaebacterial cell wall is maintained by a thick layer of peptidoglycan containing N-acetylmuramic acid, preventing lysis in extreme habitats.
- D.
The profound biochemical divergence between Archaebacteria and Eubacteria exposes a limitation in Whittaker’s system, which was later resolved by Carl Woese's three-domain classification.
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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|Archaebacteria Cell Wall Composition|Peptidoglycan_Absence
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often overgeneralize the characteristics of Kingdom Monera, assuming all members possess a peptidoglycan cell wall.
The trap relies on confusing the standard Eubacterial cell wall composition (peptidoglycan with NAM) with the unique Archaebacterial adaptation (pseudomurein/lack of peptidoglycan), which is the exact evolutionary feature that allows them to survive extreme conditions and highlights the systemic limitation of Whittaker's morphological grouping.
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 |