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Question #46166
The Question
In an experiment, a researcher introduces a synthetic double-stranded RNA (dsRNA) sequence homologous to the master regulatory Hox genes into a developing chordate embryo during early gastrulation. Which of the following best describes the primary molecular mechanism of interference and the subsequent developmental fallout?
Options
- A.
The dsRNA binds to the promoter region of the Hox genes, preventing transcription; the embryo fails to develop a notochord and dorsal hollow nerve cord.
- B.
The dsRNA is processed to form a complex that binds to and cleaves Hox mRNA, preventing translation; the embryo loses its axial patterning and fails to form the fundamental chordate trio.
- C.
The dsRNA acts as a competitive inhibitor for RNA polymerase, halting Hox mRNA synthesis; the embryo defaults to developing a ventral solid nerve cord.
- D.
The dsRNA induces a permanent frameshift mutation in the Hox gene DNA; resulting in a featureless cluster of undifferentiated cells.
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
RNA_Interference|Chordata|Developmental_Genes
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse 'gene silencing' via RNAi (post-transcriptional) with gene knockout/mutation (genomic DNA alteration) or transcriptional repression.
This question forces the synthesis of Class 12 Biotechnology (RNAi mechanism) with Class 11 Animal Kingdom (Chordate defining features), requiring the student to understand that destroying the mRNA blueprint of master regulatory genes effectively erases the organism's taxonomic identity during embryogenesis without altering its actual DNA.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Chordata Fundamental Trio |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |