Before You Begin
Question #46942
The Question
A researcher treats a mixed bacterial culture containing Methanobacterium (an Archaebacterium) and Streptococcus (a Eubacterium) with lysozyme. She observes that Streptococcus undergoes rapid cell lysis, while Methanobacterium remains completely unaffected. What is the precise biochemical reason for this differential sensitivity?
Options
- A.
The cell wall of Methanobacterium contains pseudomurein with β-1,3-glycosidic linkages, whereas lysozyme specifically cleaves β-1,4-glycosidic bonds.
- B.
Methanobacterium possesses an outer lipopolysaccharide layer that physically blocks lysozyme from reaching the peptidoglycan layer.
- C.
The cell membrane of Methanobacterium is composed of branched-chain lipids with ether linkages that are highly resistant to enzymatic degradation.
- D.
Methanobacterium lacks a cell wall entirely, relying solely on a specialized proteinaceous S-layer to prevent osmotic lysis.
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
Archaebacteria Cell Wall Composition|Lysozyme|Eubacteria|N-acetyltalosaminuronic acid
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that Archaebacteria survive extreme conditions due to 'branched-chain lipids' (NCERT fact).
The trap (Option C) exploits this by offering a true statement about Archaebacteria that is functionally irrelevant to the question.
The student must distinguish between the cell membrane's role in extremophile survival and the cell wall's biochemical composition (pseudomurein) that confers lysozyme resistance.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biological Classification - Class 11 |
| Concept | Archaebacteria Cell Wall Composition |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |