PCR & RT-PCR — Molecular Techniques & Clinical Applications

PCR & RT-PCR MCQs: practice questions

Sample PCR & RT-PCR multiple-choice questions from Molecular Techniques & Clinical Applications.

1. What is produced when PCR amplification proceeds efficiently?

   • A. Only RNA molecules
   • B. Multiple copies of the selected DNA segment
   • C. Multiple proteins
   • D. Only antibodies
   • E. Multiple chromosomes

2. What happens to DNA during the extension phase?

   • A. The DNA is translated
   • B. The protein is folded
   • C. The DNA is degraded
   • D. A complementary strand is synthesized
   • E. The chromosome is lost

3. How many copies result from one starting DNA copy after two ideal PCR cycles?

   • A. Four
   • B. Eight
   • C. Three
   • D. One
   • E. Two

4. Why is PCR useful in forensic biology?

   • A. It changes a suspect's DNA
   • B. It identifies proteins only
   • C. It prevents DNA sequencing
   • D. It eliminates contamination automatically
   • E. It can amplify DNA from very small samples

5. What is the usual temperature range for primer annealing in PCR described by Mader?

   • A. About 50–60°C
   • B. 20–30°C
   • C. 95–100°C
   • D. 72–80°C
   • E. 0–10°C

6. What is the usual temperature of the PCR denaturation step described by Mader?

7. What is the optimal extension temperature for Taq DNA polymerase in Mader's PCR description?

8. Why can PCR work with only a small amount of starting DNA?

9. Why does PCR require repeated temperature changes?

10. Which process in PCR separates the two DNA strands?

11. Which enzyme adds nucleotides to the growing DNA strand during PCR?

12. What is primer hybridization in PCR?

13. Which molecule directly provides the template for PCR amplification?

14. What is the main advantage of PCR amplification before DNA analysis?

15. Which statement about PCR is correct?

16. Why can PCR be automated?

17. How many copies result from one starting DNA copy after three ideal PCR cycles?

18. What does PCR amplify selectively?

19. What is the defining feature of a PCR chain reaction?

20. Which technique can be used to determine the nucleotide order after amplification?

21. Which enzyme is used in PCR because it tolerates the high denaturation temperature?

22. How does the amount of target DNA change after each PCR cycle?

23. What is the primary purpose of polymerase chain reaction (PCR)?

24. What is the first step of a standard PCR cycle?

25. Why are primers necessary in PCR?

26. What is the role of thermostable DNA polymerase in PCR?

27. What occurs during the extension step of PCR?

28. What is the relationship between PCR and DNA sequencing in Mader?

29. What occurs during PCR annealing?

30. What is the major limitation of PCR amplification alone?