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Question #47749
The Question
A researcher is amplifying a DNA segment using PCR. Due to a thermocycler calibration error, the extension phase is maintained at 52°C instead of the optimal 72°C. If the accumulation of DNA amplicons is mathematically modeled using population growth equations, which of the following represents the most accurate consequence of this error?
Options
- A.
Taq polymerase undergoes irreversible denaturation at this temperature, causing the intrinsic rate of increase (r) of the amplicons to become zero.
- B.
The suboptimal temperature acts as an environmental resistance factor, lowering the intrinsic rate of increase (r) and preventing the expected exponential (log) phase.
- C.
The amplification will follow a standard exponential curve (dN/dt = rN), but the carrying capacity (K) determined by dNTP availability will be drastically reduced.
- D.
The lower temperature increases the proofreading specificity of Taq polymerase, thereby increasing the intrinsic rate of increase (r) during the log phase.
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
Competent_Cell_Preparation|Biolistics/Gene_Gun_Physics|Cry_Gene_Specificity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating Biotechnology (PCR enzyme kinetics) with Ecology (Population growth models).
The trap relies on two common misconceptions: 1) Assuming suboptimal low temperatures denature enzymes (they only reduce kinetic activity, whereas high temperatures denature non-thermostable enzymes), and 2) Confusing factors that affect the rate of growth (r) with factors that determine the maximum yield or carrying capacity (K).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biotechnology : Principles and Processes - Class 12 |
| Concept | Competent Cell Preparation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |