Question

Identify the incorrect statement about restriction fragment length polymorphisms (RFLPs)?

• A. Suspects whose fragments do not match any other fragments at a crime scene can be vindicated
• B. The polymerase chain reaction can be used to produce more copies of DNA obtained at a crime scene before RFLP analysis
• C. Most RFLPs use radioactive probes
• D. Most RFLPs occur because of the repetitive nature of DNA
• E. With the advent of PCR technology, restriction enzymes are no longer needed to perform RFLP analysis

Answer 1

Answer: (E)

With the advent of PCR technology, restriction enzymes are no longer needed to perform RFLP analysis

Restriction enzyme digestion of DNA sample produces RFLPs. The DNA fragments are called RFLPs because depending on the location of restriction sites, the restriction enzymes produce DNA fragments with different length. PCR amplify the small quantities of DNA sample into the multiple ones. A variable number tandem repeat (or VNTR) refers to the presence of a short nucleotide sequence as a tandem repeat on many chromosomes; it exhibits variations in length and number of repeats between individuals. DNA fragments are then sorted according to size by gel electrophoresis. The sorted DNA fragments are then transferred from the gel to the surface of the nylon via southern blotting. Finally, radioactive probes are washed over the nylon surface to allow their joining to any DNA fragments of the same composition thereby matching different DNA samples. Thus, the correct answer is option E.