BIO 240 Crime Scene Forensics Worksheet
BIO 240 Crime Scene Forensics Worksheet
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� how forensic scientists take advantage of genomic variations in noncoding regions of DNA the techniques of polymerase chain reaction ( PCR ) and gel electrophoresis
Introduction : In recent years , law enforcement has been revolutionized by molecular biology . When human tissues are left behind at crime scenes , these tissues can be collected and processed to yield samples of DNA , which can then be treated to isolate specific DNA fragments that are highly variable in the human population . Which band pattern among Lanes 3 to 6 seems to be the closest match to the band pattern in Lane 2 , where the crime-scene DNA fragment was loaded ? Which suspect appears to be the culprit ? What is the molecular weight ( in base pairs ) of the fragment in Lane 2 ( DNA from the crime scene ), Lane 3 ( Suspect 1 ), Lane 4 ( Suspect 2 ), Lane 5 ( Suspect 3 ), and Lane 6 ( Suspect 4 )? Part C How does analyzing DNA profiles using the gel electrophoresis tool allow you to draw both qualitative and quantitative conclusions about the likely identity of the suspect in this case ? Judging by the sizes of the fragments you measured in Part C , about how many repeats of the 16-base-pair sequence would you expect to find in each of the suspect ’ s genomes ? In this lab activity , you targeted just one fragment of DNA to build the DNA profile of each suspect and the crime-scene sample . Realworld DNA profiles target multiple fragments . What is the advantage of targeting more than one fragment and having each DNA profile feature multiple bands ?