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Question #45881
The Question
A researcher is comparing the initiation and progression of DNA synthesis during in vivo replication (specifically lagging strand synthesis) and in vitro PCR amplification. Which of the following statements is NOT correct regarding the primers and their extension in these two processes?
Options
- A.
In vivo replication utilizes RNA primers because DNA polymerase cannot initiate synthesis de novo, while PCR utilizes chemically synthesized single-stranded DNA primers.
- B.
In both processes, the polymerase enzyme extends the primer strictly in the 5' -> 3' direction by adding nucleotides to a free 3'-OH group.
- C.
During in vivo lagging strand synthesis, DNA ligase removes the RNA primers and joins the Okazaki fragments, whereas in PCR, the synthetic DNA primers become a permanent part of the final amplicon.
- D.
Mismatched annealing of primers in PCR results in non-specific amplification, whereas in vivo, the high fidelity and proofreading activity of DNA polymerase minimize such replication errors.
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|Taq Polymerase|Ori Sequence
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often conflate the entire process of 'Okazaki fragment maturation' into a single step attributed to DNA ligase, forgetting that primer removal and gap filling are distinct enzymatic steps performed by DNA Polymerase before ligase can act.
Furthermore, contrasting the transient RNA primers of in vivo replication with the permanent DNA primers of PCR highlights a deep, synthetic understanding of Biotechnology versus Molecular Biology.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Molecular Basis of Inheritance - Class 12 |
| Concept | Okazaki Fragment Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |