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Question #47541
The Question
A population of homosporous pteridophytes successfully germinates to form mature, photosynthetic prothalli. However, a sudden and prolonged environmental humidity deficit occurs in the microhabitat. Despite the prothalli remaining metabolically active, the population fails to expand. Which of the following best explains the exact bottleneck in their life cycle?
Options
- A.
Absence of a continuous water film prevents the chemotactic swimming of antherozoids toward the archegonial neck, halting sporophyte initiation.
- B.
The monoecious prothallus fails to undergo meiosis to produce the next generation of spores due to severe desiccation.
- C.
The archegonia fail to secrete malic acid, which is essential to attract the non-motile male gametes.
- D.
The independent, free-living sporophyte is unable to establish its primary root system in the dry soil.
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
Bryophyte Sporophyte Anatomy|Predator-Prey Oscillations|Population Growth Model Dynamics
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize 'water is needed for fertilization' but fail to pinpoint the exact mechanistic bottleneck (chemotaxis of flagellated antherozoids in a water film) or confuse the ploidy and events of the prothallus.
The trap in Option B exploits the misconception that gametophytes produce spores, while Option C tests the morphology of male gametes (motile vs non-motile in gymnosperms/angiosperms).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Bryophyte Sporophyte Anatomy |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |