Question

Which of the following best describes why PCR protocols contain numerous cycles of the denaturation/annealing/extension steps?

a) To reduce the time required for the PCR reaction
b) To increase the specificity of DNA amplification
c) To save on reagents and reduce costs
d) To decrease the number of steps in the PCR process

Answer 1

PCR protocols consist of numerous cycles of denaturation, annealing, and extension to exponentially amplify the target DNA sequence, resulting in sufficient quantities of DNA for analysis.

Step-by-step explanation:

The numerous cycles of denaturation, annealing, and extension steps in PCR protocols are necessary to increase the quantity of DNA that is being targeted for amplification. Each cycle doubles the amount of double-stranded target DNA copies, which enhances the overall yield of the amplified product. Typically, 25-40 cycles are included in PCR protocols, allowing for exponential amplification, starting from tens of millions to potentially over a trillion copies of the target DNA sequence. This is essential to ensure there is enough DNA for subsequent analyses and applications.Therefore, the best description of why PCR protocols contain numerous cycles of the described steps is to increase the specificity of DNA amplification, as these repeated cycles are crucial for exponentially amplifying the target DNA sequence to a sufficient quantity that can be used for further experimentation and analysis.