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Victoria Police forensic scientists conduct DNA profiling using samples taken from crime scenes - VCE - SSCE Biology - Question 2 - 2007 - Paper 1
Question 2
Victoria Police forensic scientists conduct DNA profiling using samples taken from crime scenes. Traces of DNA of less than 1 nanogram can be amplified and then prof... show full transcript
Worked Solution & Example Answer:Victoria Police forensic scientists conduct DNA profiling using samples taken from crime scenes - VCE - SSCE Biology - Question 2 - 2007 - Paper 1
Step 1
Step 2
b. What must be done between stages 1 and 2 to separate the strands of the DNA molecule?
Answer
Heating must be applied to the DNA sample to a temperature of 90°C or greater. This heating allows the hydrogen bonds between the two strands of the DNA molecule to break, resulting in the separation of the strands.
Step 3
c. Complete and label the diagram at stage 2.
Answer
In the diagram for stage 2, the primers should be shown at opposite ends of the DNA strands labeling the 3' end for each primer, indicating where they attach. Then, illustrate the addition of DNA polymerase, which is added to propagate DNA synthesis away from the primers. Label the temperature condition for the reaction to be at approximately 50°C.