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Repeating DNA Fingerprinting

Decent Essays

Introduction DNA is “the hereditary material in humans and almost all other organisms,” (NIH, 2016). It’s composed of nucleotides which contain a nitrogen base (A, C, G, and T), phosphate group, and a sugar group. The DNA is found within the nucleus where it\s tightly packed into a chromosome. Its structure is a double helix, that’s wrapped around a nucleosome. This structure forms a string of beads that’re coiled about each other. This new structure is now called a thread. Next, the structure is looped, forming a looped chromatin, which will then condense forming a condense chromatin. Furthermore, the genome is formed, which is the complete set of genes or genetic material in an organism. Finally, when the cell breaks down it releases DNA, …show more content…

The DNA samples have unique patterns, which consist of polymorphisms (repeating DNA sequences) that are unique to each family. Repeating DNA sequences include variable number tandem repeats (vNTR), which are 9 to 80 nucleotides in length, and short tandem repeats (STR), which are 2 to 8 nucleotides in length. When comparing two individual’s DNA, their sugar-phosphate “backbone’ arrangement, as well as the base pairs will be the same. The only difference is the “order of these bases,” (Rettner, R. 2013) which determines the DNA's instructions, or genetic code. Thus, when comparing two sample of DNA, the linear order of the base pair must be the same, in order for the DNA samples to be …show more content…

Since it’s almost impossible for two people to have the same DNA, being 30,000 million to 1 (except for identical twins), this technique allows scientists to help find the criminal. Gel electrophoresis lets scientists to compare the DNA patterns of the crime scene, victim, and different suspects in order to see if any individual’s DNA pattern match to the one of the crime scene. If the crime scene DNA pattern matches to the suspect’s DNA pattern, it’s very likely that he/she committed the crime.

The purpose of the biotech lab is to investigate the DNA sample of five different suspects with the DNA sample of the crime scene in order to identify which suspect committed the crime. This will be done through the process of DNA fingerprinting, where the DNA samples of the suspects and crime scene will be injected to the well of the gel electrophoresis, where the DNA patterns can be analyzed. The DNA pattern will allow the experimenters to determine who committed the crime by matching the DNA pattern of a suspect to the one of the crime

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