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Question #45247
The Question
In a large, randomly mating population of Biston betularia, the allele for dark wing color (D) is dominant over the allele for light wing color (d). Following rapid industrialization, strong directional selection favors the dark phenotype, disrupting the population's genetic steady state. Which of the following statements regarding this evolutionary shift is INCORRECT?
Options
- A.
The observed frequency of the 'dd' genotype will become significantly lower than the expected q^2 calculated from the pre-industrial allele frequencies.
- B.
Because the Hardy-Weinberg equilibrium is disrupted by selection, the sum of the observed genotype frequencies in the surviving population will deviate from 1.
- C.
The relative fitness of the 'dd' genotype becomes less than that of the 'DD' and 'Dd' genotypes, driving a continuous shift in allele frequencies.
- D.
The recessive allele (d) is protected from immediate elimination because it remains hidden from natural selection in the heterozygous (Dd) state.
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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
Hardy-Weinberg Equilibrium Variables|Natural Selection Directionality|Industrial Melanism
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: The mathematical distinction between the sum of observed genotype frequencies (always 1) and the Hardy-Weinberg expected frequencies.
Common Misconception: Students memorize the equation 'p^2 + 2pq + q^2 = 1' as the definition of equilibrium and incorrectly assume that if a population is undergoing natural selection (violating equilibrium), the sum of its genotype frequencies will no longer equal 1.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biomolecules - Class 11 |
| Concept | Metabolic Flux and Steady State |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |