Before You Begin
Question #45311
The Question
In a population of Oxalis, severe environmental stress triggers a complete shift from chasmogamous to cleistogamous flower production. While this adaptation guarantees an assured seed set even in the absence of pollinators, it fundamentally alters the population's genetic trajectory. Which of the following represents the correct physiological bypass and its subsequent genetic fallout?
Options
- A.
It bypasses dichogamy and herkogamy, leading to obligate autogamy and the rapid phenotypic expression of deleterious recessive mutations.
- B.
It bypasses self-incompatibility, promoting obligate geitonogamy which maintains a stable Hardy-Weinberg equilibrium.
- C.
It bypasses protandry, shifting the plant to apomictic seed development to prevent inbreeding depression.
- D.
It bypasses heterostyly, resulting in forced allogamy and a sudden increase in hybrid vigor.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Cleistogamy vs Chasmogamy|Outbreeding Device Logic|Genotype_Homozygosity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often focus solely on the evolutionary advantage of cleistogamy (assured seed set) and miss its severe long-term genetic cost (inbreeding depression).
The trap lies in distinguishing between autogamy and geitonogamy, and understanding that while outbreeding devices (like dichogamy) normally prevent autogamy, the physical closure of cleistogamous flowers forcefully bypasses these mechanisms, inevitably leading to the accumulation of homozygous recessive mutations.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Sexual Reproduction in Flowering Plants - Class 12 |
| Concept | Outbreeding Device Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |