Q14 - Identifying the First Limiting Reagent in a Multi-Cycle PCR Reaction

One cycle of the PCR reaction doubles the number of DNA fragments. Further, each time one cycle of the PCR reaction progresses, the primer pair, the substrate dNTP, and the DNA polymerase molecule are required in double amount, so the amount of these components limits the overall amount of DNA that can be synthesized in PCR. The length of the DNA fragment to be amplified was 100 base pairs including the primers, and the PCR reaction was started with the primer length of 20 bases. The four types of bases are evenly distributed and PCR amplification efficiency is 100%. As the reaction progresses, it will not be completed due to running out of one of the components in a certain cycle. Template DNA fragment: 4 copies. Primer: 1,000 sets. dNTPs (dATP, dTTP, dGTP, dCTP): 48,000 molecules (12,000 each). DNA polymerase: 1,200 molecules.

Using the information and data, determine which of the statements are true or which are false.

Question reproduced from IBO 2020, Theoretical Exam 2, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)