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Question #47467
The Question
A test cross of an F1 dihybrid plant (AaBb) with a double recessive parent (aabb) yields the following progeny: 410 Aabb, 410 aaBb, 90 AaBb, and 90 aabb. Based on the principles of inheritance, all of the following statements regarding this cross are correct, EXCEPT:
Options
- A.
The genes controlling these traits are physically linked on the same chromosome with a distance of 18 map units.
- B.
The original homozygous parents that were crossed to produce the F1 dihybrid had the genotypes AABB and aabb.
- C.
The F1 dihybrid failed to exhibit Mendel's Law of Independent Assortment during gametogenesis.
- D.
The physical association between the two genes restricted the recombination frequency to less than 50 percent.
Check Your Answer
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
Chromosomal_Crossing_Over|Linkage_Groups|Gamete_Ratio
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often blindly assume that all F1 dihybrids (AaBb) originate from a cross between completely dominant (AABB) and completely recessive (aabb) parents (cis arrangement).
This question tests their ability to deduce the actual parental genotypes by identifying the highest frequency progeny classes in a linkage scenario, distinguishing between cis and trans linkage phases.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Neural Control and Coordination - Class 11 |
| Concept | Ipsilateral vs Contralateral Signaling |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |