Answer:
a. Amplifies DNA through an exponential process utilizing a thermostable polymerase, site specific primers, and a temperature cycle.
Explanation:
Polymerase chain reaction, PCR is a technique to make copies of a small amount of DNA. The process uses high temperature (around 95 degrees Celsius) to separate the DNA strands of the sample followed by annealing of site-specific primers to facilitate the formation of new DNA strands. Annealing is done at relatively lower temperatures (around 55 degrees Celsius).
To withstand the higher temperatures, the Taq polymerase enzyme is used that has an optimum temperature range of 75-80 degrees Celsius. The enzyme is isolated from Thermophilus aquaticus, found in hot water springs. One DNA double helix makes two DNA helices by one round of PCR. Both the newly formed DNA helices enter the next round to make 4 DNA helices. The process continues to make the desired copies of the sample DNA in an exponential pattern.