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Question #47496
The Question
A researcher attempts to use a standard bacteriophage (which normally infects eubacteria) to mediate horizontal gene transfer via transduction in a methanogen. The experiment fails completely at the initial stage of viral adsorption. Which of the following structural features of the methanogen is primarily responsible for this evolutionary barrier?
Options
- A.
The presence of branched-chain lipids in the cell membrane that electrostatically repel the viral capsid.
- B.
The absence of N-acetylmuramic acid (NAM) and D-amino acids in its cell wall, preventing specific receptor-ligand docking.
- C.
The presence of a rigid cellulosic cell wall that physically blocks the penetration of the viral tail core.
- D.
The secretion of restriction endonucleases that degrade the viral genome immediately upon contact.
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
Bacteriophage Genetic Material|RNAi Vector Source|Chromatin Condensation
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize 'Archaebacteria have different cell walls' and 'Viruses are host-specific' as isolated facts.
This question forces the synthesis of these concepts, testing the understanding that viral host specificity is biochemically dictated by cell wall composition (peptidoglycan vs. pseudomurein).
It also tests the chronological sequence of viral infection, using 'initial stage of viral adsorption' to eliminate post-entry defense mechanisms like restriction endonucleases.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biological Classification - Class 11 |
| Concept | Bacteriophage Genetic Material |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |