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Question #45340
The Question
A biotechnology firm successfully introduces a foreign gene into an apomictic hybrid crop using Agrobacterium tumefaciens-mediated transformation. However, farmers report that the seeds collected from these transgenic plants exhibit segregation of characters and a complete loss of hybrid vigor in the subsequent generation. What is the most scientifically accurate explanation for this phenomenon?
Options
- A.
The T-DNA randomly integrated into the apomixis-controlling genomic region, causing insertional mutagenesis and reverting the plant to sexual reproduction.
- B.
The introduced foreign gene triggered RNA interference (RNAi) against the apomictic regulatory genes, inducing normal meiosis.
- C.
Agrobacterium infection inherently overrides the apomictic pathway by inducing reductional division in the megaspore mother cell.
- D.
The transformation process induced somaclonal variation, causing the apomictic embryos to undergo genetic recombination prior to seed maturation.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
T-DNA|Ti_Plasmid|Clonal_Integrity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize 'apomixis maintains hybrid vigor' and 'Agrobacterium is a cloning vector' in isolation.
The pivot requires synthesizing these two NCERT concepts: recognizing that Agrobacterium's random T-DNA integration can cause insertional mutagenesis.
If this mutagenesis disrupts the apomixis-controlling gene, the plant loses its 'genetic fixity' and reverts to Mendelian segregation, destroying the hybrid vigor.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Sexual Reproduction in Flowering Plants - Class 12 |
| Concept | Apomixis Genetics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |