2. It is a technique used to produce large quantities of replicated DNA.

3. One of its uses is when having to analyze something of which you don’t have a lot of sample because by having larger quantities, the analysis is easier. Examples: blood, semen, hair, saliva and other tissues (amplified using PCR).

4. The PCR is required at high temperatures and also needs the help of the polymerase enzyme, found in Thermus aquaticus (bacteria).

5. The DNA fragment of interest is taken away along with some nucleotides, primers and the enzyme. They are placed at temperatures around 95°C so that it can be denatured (breaking hydrogen bonds that hold together the structure). Primer: a strand of nucleic acid that serves as a starting point for DNA synthesis.

6. The temperature is reduced to 60°C so primers can form hydrogen bonds with the complementary base pairs of the DNA (following base pair rules).

7. The temperature is raised to 72°C, so the enzyme works efficiently and begins polymerizing until both strands of the DNA are created. This process repeats various times, having as a result, many copies of the same DNA fragment.

9. http://www.sumanasinc.com/webcontent/animati ons/content/pcr.html http://www2.le.ac.uk/departments/emfpu/genetic s/explained/images/PCR-process.gif/image http://openwetware.org/images/f/f5/CH391L_S12 _PCR_process.gif