Answer:
First step:
B. DNA is heated to break the hydrogen bonds that hold the two strands together
Second step:
D. DNA is cooled to allow the primers to bind to the DNA strands Primers
Explanation:
Polymerase chain reaction, or commonly called PCR, is a molecular technique invented by Katy Mullis in the 1980's. It is used to amplify a sequence of DNA template to form several copies.
The process of polymerase chain reaction occurs in three major steps viz;
Step 1: In this step, the DNA template is denatured by heating it to a high temperature. This is done to separate the double stranded molecule into single strands by breaking the hydrogen bonds holding the nucleotides base together.
Step 2: Next, the temperature is reduced or allowed to cook in order for short DNA fragments called PRIMERS to bind to the site on the DNA strands. This step is called ANNEALING.
