IB DP Biology- D1.1 DNA replication - IB Style Questions For SL Paper 1A -New Syllabus
▶️ Answer/Explanation
Answer: B. During replication of the DNA that has been cut with restriction enzymes
Explanation:
DNA profiling is a laboratory technique used to identify individuals by analyzing specific regions of their DNA.
The polymerase chain reaction (PCR) is a method that creates millions of copies of a targeted DNA segment. In DNA profiling, PCR is used after restriction enzymes have cut the DNA to amplify these fragments, making them easier to detect and analyze during subsequent steps like gel electrophoresis.
Answer Evaluation:
A. Incorrect – Extraction is the process of isolating DNA from cells. PCR is not used during extraction.
B. Correct – PCR amplifies (copies) the DNA fragments after they have been cut with restriction enzymes, allowing further analysis.
C. Incorrect – Electrophoresis is a separation technique based on fragment size; it does not involve replication or amplification.
D. Incorrect – Incubation with labelled probes is used for detecting specific DNA sequences, not for replication.