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Question #46555
The Question
Many plants synthesize energy-intensive alkaloids (e.g., nicotine, strychnine) as a chemical defense against phytophagous insects. If severe habitat fragmentation—a primary driver of the 'Evil Quartet'—causes the local extinction of these specific insect herbivores, what is the most likely long-term evolutionary consequence for the plant population?
Options
- A.
The plant will face co-extinction due to the loss of its obligate co-evolutionary partner.
- B.
Alkaloid biosynthesis will become a metabolic burden, leading to a gradual evolutionary reduction in its production due to relaxed selection pressure.
- C.
The plant will immediately reverse the alkaloid pathway to synthesize primary metabolites like glucose for rapid growth.
- D.
The plant will increase alkaloid exudation into the soil to competitively exclude alien plant species.
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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
Coca Alkaloids|Evil Quartet Drivers|Secondary Metabolites
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize the 'Evil Quartet' (Habitat loss, Overexploitation, Alien species, Co-extinction) and 'Chemical Defenses' (Alkaloids) as isolated NCERT facts.
The pivot requires synthesizing these concepts: understanding that chemical defense is an evolutionary response to predation.
If the predator is removed via habitat fragmentation, the defense mechanism loses its adaptive value and becomes a metabolic liability (Resource Allocation/Fitness Cost).
A common misconception is confusing 'co-extinction' (which applies to obligate mutualisms or host-parasite relationships) with predator-prey dynamics.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Human Health and Disease - Class 12 |
| Concept | Opioids/Cannabinoids/Coca Alkaloids |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |