Question

The difference between PCR and real-time PCR is that real-time PCR:

A. can amplify DNA a billion-fold within just a few hours, while standard PCR cannot.

B. requires primers, while standard PCR does not.

C. can determine the DNA sequence, while standard PCR cannot.

D. can measure the amount of DNA amplified as the reaction proceeds, while standard PCR cannot.

E. uses DNA polymerase, while standard PCR does not.

Answer 1

Real-time PCR calculates the amount of DNA amplified by measuring the amount of mRNA.

A. can amplify DNA a billion-fold within just a few hours, while standard PCR cannot.- It is incorrect as both can amplify the DNA.

B. requires primers, while standard PCR does not.- it is incorrect as both require primers.

C. can determine the DNA sequence, while standard PCR cannot.- It is incorrect as both cannot determine the sequence.

D. can measure the amount of DNA amplified as the reaction proceeds, while standard PCR cannot.- It is correct as real-time PCR uses reverse transcriptase to perform reverse transcription before the polymerase chain reaction. It detects the amount of gene amplification.

E. uses DNA polymerase, while standard PCR does not.- This is incorrect as both require a DNA polymerase.

So, the correct answer is D.