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Question #45309
The Question
A population of Oxalis possesses a gene for petal color that exhibits incomplete dominance (R = Red, r = White, Rr = Pink). If a specific lineage of this plant reproduces exclusively via cleistogamous flowers for several consecutive generations, which of the following represents the most accurate genetic consequence?
Options
- A.
The pink phenotype will progressively diminish, sequestering the population into homozygous red and white lineages, thereby rendering test crosses redundant.
- B.
The pink phenotype will become fixed as a pure line because strict autogamy prevents the introduction of new alleles from outcrossing.
- C.
The population will maintain a stable 1:2:1 phenotypic ratio because the absence of external pollinators preserves the Hardy-Weinberg equilibrium.
- D.
The frequency of the white phenotype will continuously decrease due to the accumulation of lethal mutations associated with inbreeding depression.
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|Test Cross vs Back Cross Ratios|Incomplete Dominance Pheno-Geno
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that cleistogamy leads to pure lines, but fail to mathematically apply this to heterozygote frequency (which halves each generation).
Furthermore, they must synthesize this with the purpose of a test cross, realizing that in a guaranteed homozygous pure line, testing for hidden recessives is entirely redundant.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Sexual Reproduction in Flowering Plants - Class 12 |
| Concept | Cleistogamy vs Chasmogamy |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |