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Question #45999
The Question
In many pioneer plant species, seed dormancy is broken by a specific ratio, preventing germination deep in the soil or under a dense canopy. If a loss-of-function mutation in the phytochrome genes causes these seeds to germinate irrespective of light quality directly beneath the parent plant, which of the following represents the most likely ecological consequence and the subsequent evolutionary shift?
Options
- A.
Complete niche overlap leading to intense intraspecific competition, where the resulting high seedling mortality shifts selection pressure toward r-selected traits.
- B.
Resource partitioning between the parent and offspring, reducing intraspecific competition and favoring K-selected traits.
- C.
Competitive exclusion of the parent plant by the rapidly germinating seedlings, leading to a climax community.
- D.
Induction of secondary dormancy due to far-red light enrichment, minimizing niche overlap and promoting r-selected traits.
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
Seed_Bank_Dynamics|Competition|Germination_Timing
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating Plant Physiology (Phytochrome-mediated dormancy) with Ecology (Niche Overlap and r/K selection).
Students often study these units in isolation.
The trap is failing to realize that breaking dormancy at the wrong spatial location (under the parent) maximizes intraspecific competition.
This acts as a severe mortality factor, which ecologically drives a shift toward r-selection (quantity over quality) rather than K-selection, despite the presence of competition.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Growth and Development - Class 11 |
| Concept | Seed Dormancy Breaking |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |