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Question #45606
The Question
In a diploid plant species, leaf color is governed by a multiple allelic series at a single locus with the dominance hierarchy C¹ (Dark Green) > C² (Light Green) > C³ (Yellow). Stem height is controlled by a linked locus 24 map units away, with alleles T (Tall) > t (Dwarf). A plant heterozygous for both loci with the genotype C¹ t / C² T (trans-arrangement) is test-crossed with a yellow-leaved, dwarf plant. Which of the following statements regarding the expected F₁ progeny is CORRECT?
Options
- A.
12% of the progeny will exhibit dark green leaves and tall stems.
- B.
25% of the progeny will exhibit yellow leaves due to independent assortment.
- C.
The phenotypic ratio of dark green to light green leaves in the progeny will be 3:1.
- D.
38% of the progeny will represent the total recombinant phenotypes.
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
Drosophila|Body_Color|Eye_Color|Map_Units
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often mechanically apply Mendelian dihybrid ratios (like 1:1:1:1 for test crosses) without adjusting for linkage (trans-arrangement) and recombination frequency.
Furthermore, they conflate multiple allelism in a population with the alleles present in a single diploid individual, falsely assuming a recessive C³ phenotype can appear if they treat the cross as a standard independent assortment problem.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Principles of Inheritance and Variation - Class 12 |
| Concept | Multiple Allelism Limitation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |