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Question #46586
The Question
Methanogens in the rumen of cattle rely on the H2 and CO2 produced by cellulolytic bacteria during the fermentation of roughage. If a cow is abruptly shifted from a high-roughage diet to a high-protein, low-fiber concentrate, which of the following statements correctly identifies the ecological fallout and the nature of the interaction between these two microbial groups?
Options
- A.
The interaction is amensalism (-, 0); the high-protein diet directly kills methanogens, allowing cellulolytic bacteria to thrive due to reduced competition for rumen space.
- B.
The interaction is commensalism (+, 0); cellulolytic bacteria decline due to low fiber, but methanogens survive by shifting their metabolism to utilize amino acids for methanogenesis.
- C.
The interaction is mutualistic syntrophy (+, +); the decline of cellulolytic bacteria deprives methanogens of their substrate, leading to a collapse of both populations and a drop in rumen pH.
- D.
The interaction is parasitism (+, -); methanogens consume the host's dietary protein, leading to an increase in rumen pH and the competitive exclusion of cellulolytic bacteria.
Check Your Answer
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
Ruminants|Cellulolytic_Bacteria|Methanogens
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that methanogens live in the rumen (NCERT Biological Classification) but fail to connect it to the ecological interaction matrix (NCERT Organisms and Populations).
The trap lies in assuming methanogens can adapt their metabolism to any diet (Option B) or failing to recognize that the removal of one species in an obligate mutualistic (+, +) syntrophic relationship leads to the collapse of the other.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Microbes in Human Welfare - Class 12 |
| Concept | Methanogens Metabolism |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |