Refer to the figure. Through the use of linkage analysis, a researcher has identified a candidate gene responsible for a novel neurological disease.To obtain enough sample for DNA fingerprinting, the researcher uses PCR to amplify the gene.From the parent's DNA, PCR amplifies one band.From the child's DNA, the same size band plus a second larger band is amplified.Based on the published sequence of the gene, the researcher knows that restriction enzyme A will cut the wild-type allele into two fragments.The fragment sizes identified by DNA gel electrophoresis are shown in the figure.What technique should the researcher next use to identify the nature of the mutation with certainty?
A) DNA fingerprinting
B) DNA linkage analysis
C) DNA sequencing
D) Gel electrophoresis
E) Genetic screening

Question

Refer to the figure.  Through the use of linkage analysis, a researcher has identified a candidate gene responsible for a novel neurological disease.To obtain enough sample for DNA fingerprinting, the researcher uses PCR to amplify the gene.From the parent's DNA, PCR amplifies one band.From the child's DNA, the same size band plus a second larger band is amplified.Based on the published sequence of the gene, the researcher knows that restriction enzyme A will cut the wild-type allele into two fragments.The fragment sizes identified by DNA gel electrophoresis are shown in the figure.What technique should the researcher next use to identify the nature of the mutation with certainty?
A) DNA fingerprinting 
B) DNA linkage analysis 
C) DNA sequencing 
D) Gel electrophoresis 
E) Genetic screening

Quizplus · Accepted Answer

The best way to identify the nature of the mutation with certainty is through DNA sequencing. This will allow the researcher to determine the exact sequence of the amplified gene in both the parent and the child, and to identify any differences or mutations in the child's sequence that may be responsible for the observed band pattern in the gel electrophoresis. DNA fingerprinting, DNA linkage analysis, gel electrophoresis, and genetic screening are all useful techniques in molecular biology, but they may not provide the same level of precision and specificity as DNA sequencing in this particular case.

Refer to the Figure