Before You Begin
Question #45821
The Question
In a diploid plant species (), a test cross of a dihybrid () yields the following progeny: 40% , 40% , 10% , and 10% . Based on the principles of linkage and genetic recombination, which of the following statements is INCORRECT?
Options
- A.
The plant genome comprises exactly 7 linkage groups.
- B.
The genes A and B are located on the same chromosome, separated by a distance of 20 centiMorgans.
- C.
During gametogenesis in the dihybrid parent, the alleles assort independently to produce gametes in a 1:1:1:1 ratio.
- D.
If the dihybrid parent had the alleles in a trans (repulsion) arrangement, the expected frequency of progeny in the test cross would be 10%.
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|Mendelian Gamete Frequency|Chromosomal Theory of Inheritance
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that a dihybrid produces 4 gamete types but fail to recognize that linkage fundamentally violates Mendel's Law of Independent Assortment, shifting the 1:1:1:1 gamete ratio to favor parental combinations.
Furthermore, calculating the exact frequency of a homozygous recessive offspring requires identifying whether the linked genes are in a cis (coupling) or trans (repulsion) phase.
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 |