Answer:
The polymerase chain reaction (PCR) is used to make millions of copies of a target piece of DNA. It is an indispensable tool in modern molecular biology and has transformed scientific research and diagnostic medicine.
PCR and its variations have a wide range of specialised applications and are used by scientists in all fields of biology. The results are also used by scientists in many other fields.
Modern biotechnology introduces some of the ways in which DNA technologies have changed what scientists are able to do.