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Question #45592
The Question
In Antirrhinum majus, flower color exhibits incomplete dominance. A pink-flowered plant is crossed with a white-flowered plant. Which of the following statements regarding this cross is INCORRECT?
Options
- A.
The phenotypic ratio of the resulting progeny perfectly mirrors their genotypic ratio.
- B.
The cross yields a 1:1 ratio of dominant to recessive phenotypes, confirming the heterozygosity of the pink parent.
- C.
The genotypic segregation ratio obtained is mathematically identical to that of a standard Mendelian monohybrid test cross.
- D.
Exactly 50% of the offspring produced from this cross will possess a homozygous genotype.
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
Incomplete Dominance Pheno-Geno|Test Cross vs Back Cross Ratios
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that a 'test cross yields a 1:1 ratio' and is used to 'confirm heterozygosity'.
When reading Option B, they recognize these familiar phrases and accept the statement as true, failing to notice the critical terminology trap: in incomplete dominance, the heterozygote expresses an 'intermediate' phenotype, not a 'dominant' one.
This tests the student's ability to distinguish between Mendelian dominance and incomplete expression during Genotype-Phenotype mapping.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Principles of Inheritance and Variation - Class 12 |
| Concept | Test Cross vs Back Cross Ratios |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |