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Question #45892
The Question
During the optimization of a PCR protocol for viral load detection, a technician mistakenly designs both the forward and reverse primers to be complementary to the 5' flanking regions of the target sequence on the template (non-coding) and coding strands, respectively. Assuming standard PCR conditions, what will be the direct consequence of this design error?
Options
- A.
Taq polymerase will synthesize DNA in the 3' to 5' direction to compensate for the orientation, yielding a mutated amplicon.
- B.
The primers will fail to anneal to the denatured DNA strands during the cooling phase due to incorrect polarity.
- C.
Taq polymerase will extend the primers away from the target sequence, resulting in zero amplification of the viral gene.
- D.
Linear amplification of the target sequence will occur instead of exponential amplification.
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
PCR Primer Design|Non-Coding Strand|Taq Polymerase
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that primers bind to the 'ends' of a gene but fail to visualize the antiparallel nature of DNA combined with the strict 5' to 3' directionality of DNA polymerase.
This question tests the spatial orientation of primer binding; if primers bind to the 5' ends of the target region, their 3'-OH groups point away from the target, making target amplification impossible.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Molecular Basis of Inheritance - Class 12 |
| Concept | Non-Coding Strand Utility |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |