Before You Begin
Question #46066
The Question
An alien insect species invades a localized ecosystem and completely outcompetes the native Tegeticula moths, leading to their local eradication. Over the next few years, despite optimal soil, water, and light conditions, the native Yucca plant population completely crashes. Which of the following best identifies the primary driver from the 'Evil Quartet' and the exact biological mechanism responsible for the plant's local extinction?
Options
- A.
Alien species invasion; the invasive insect competitively excludes the plant by secreting allelochemicals that inhibit Yucca seed germination.
- B.
Co-extinction; the plant faces a reproductive dead-end because it relies exclusively on the moth for pollination and oviposition-linked seed set.
- C.
Co-extinction; the loss of the moth deprives the plant of its obligate defense mutualist, leading to overgrazing by native herbivores.
- D.
Habitat fragmentation; the invasive species disrupts the micro-habitat, preventing the plant from absorbing essential soil nutrients.
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
Eichhornia crassipes|Water Body Eutrophication|Z-slope modification
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Recognizing that while 'Alien species invasion' is the initiating event, the actual crash of the Yucca population is a classic textbook example of 'Co-extinction' driven by the breakdown of an obligate mutualism (pollination).
Common Misconception: Students often confuse the initiating cause (alien invasion) with the direct mechanism of the host's demise (co-extinction due to reproductive failure).
Furthermore, they might confuse the Yucca-moth pollination mutualism with defense mutualisms.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biodiversity and Conservation - Class 12 |
| Concept | Alien Species Invasion Impacts |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |