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What is a DNA probe? A DNA probe is a short single strand of DNA that is used to detect specific base sequences of DNA - AQA - A-Level Biology - Question 8 - 2019 - Paper 1
Question 8
What is a DNA probe? A DNA probe is a short single strand of DNA that is used to detect specific base sequences of DNA. It binds complementary sequences, allowing f... show full transcript
Worked Solution & Example Answer:What is a DNA probe? A DNA probe is a short single strand of DNA that is used to detect specific base sequences of DNA - AQA - A-Level Biology - Question 8 - 2019 - Paper 1
Step 1
Describe how the DNA is broken down into smaller fragments.
Answer
The DNA is broken down into smaller fragments using restriction endonucleases, which are enzymes that cut the DNA at specific base sequences. This process fragments the DNA into manageable pieces, enabling further analysis.
Step 2
The DNA on the nylon membrane is treated to form single strands. Explain why.
Answer
The DNA on the nylon membrane is treated to form single strands so that the DNA probes can effectively bind to their complementary sequences. This binding is crucial for the detection of specific DNA sequences.
Step 3
Lane 1 of Figure 7 enabled the size of the different viral fragments to be determined. Suggest and explain how.
Answer
Lane 1 contains DNA fragments of known sizes, which serve as a reference. By comparing the migration distance of the viral fragments against these known sizes, the sizes of the different viral fragments can be accurately determined.
Step 4