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There were three suspects in an assault case - VCE - SSCE Biology - Question 5 - 2002 - Paper 1
Question 5
There were three suspects in an assault case. A forensic scientist found blood, other than the victim's, at the site. DNA was extracted from five blood samples. - th... show full transcript
Worked Solution & Example Answer:There were three suspects in an assault case - VCE - SSCE Biology - Question 5 - 2002 - Paper 1
Step 1
a. Explain the role of the polymerase enzyme in PCR.
Answer
The polymerase enzyme catalyzes the production of a new strand of DNA or is involved in making multiple copies of DNA, referred to as amplification. This enzyme operates by extending the DNA strand using the original DNA template. It ensures the accurate addition of nucleotides based on the complementary base pairing, creating a new double-stranded product.
Step 2
b. Name two properties of the DNA fragments which allow them to be separated from each other during gel electrophoresis.
Answer
- Charge: DNA fragments are negatively charged due to their phosphate backbone, enabling them to move towards the positive pole of the gel during electrophoresis.
- Size: Smaller DNA fragments migrate faster through the gel matrix compared to larger fragments, allowing for separation based on size.