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Question #45817
The Question
In a diploid plant species (2n = 14), genes for flower color and leaf size exhibit incomplete dominance, while genes for seed shape show complete dominance. Which of the following statements correctly identifies the number of linkage groups in this plant and the impact of these allelic interactions on genetic mapping?
Options
- A.
The plant has 14 linkage groups, as incomplete dominance prevents the independent assortment of homologous chromosomes.
- B.
The plant has 7 linkage groups, because linkage groups correspond to the haploid chromosome number and are strictly independent of intra-allelic interactions.
- C.
The plant has 7 linkage groups, but the physical distance between linked genes will appear altered due to the identical phenotypic and genotypic ratios (1:2:1) of incomplete dominance.
- D.
The plant has 14 linkage groups, because the intermediate phenotypes create new linkage associations during meiotic prophase I.
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
Linkage Group Calculation|Incomplete Dominance Pheno-Geno|Chromosomal Theory of Inheritance
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between physical chromosomal mapping (Linkage) and gene expression patterns (Incomplete Dominance).
Students often conflate complex phenotypic ratios with physical chromosomal alterations.
The primary trap is Option C, which uses a correct NCERT fact (the 1:2:1 ratio of incomplete dominance) as a 'Common Half-Truth' to justify an incorrect conclusion about genetic mapping and physical distance.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Principles of Inheritance and Variation - Class 12 |
| Concept | Linkage Group Calculation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |