page 03 3. The graph shows how temperature changes during repeated cycles of a polymerase chain reaction (PCR). 10 9 8 7 6 5 temperature (°C) time (minutes) 4 3 2 1 0 100 90 80 70 60 50 If there were 500 molecules of DNA at the start, predict how many copies there will be after 20 minutes. A 16 000 B 8000 C 2500 D 2000 4. DNA from a mother, child and four men (A, B, C and D) in a paternity suit was analysed. The DNA was amplified using PCR and separated by gel electrophoresis. From the results shown in the diagram, identify the likely father of the child. D C B A Mother Child [Turn over