Answer:
This question lacks options, the options are:
A. The DNA sample comes from a bacterium or virus,
B. The DNA sample has been cut into fragments by restriction enzymes.
C. Only a small amount of the DNA sample is available,
D. The DNA sample includes regions that are transcribed into mRNA
The answer is C
Explanation:
Polymerase chain reaction, commonly known as PCR, is a molecular technique used to amplify a DNA sample into producing million copies of it. The PCR was invented by Kary Mullis in 1983 and since then it has been used to multiply DNA sample for use in molecular or forensic studies.
PCR starts with a very minute fragment of DNA sample. Therefore, scientists use the polymerase chain reaction (PCR) before they analyze a DNA sample under the condition that only a small amount of the DNA sample is available.
