Chapter 9 Exam 2 Flashcards
What is DNA fingerprinting and when was it developed?
developed in 1975 in England by Dr. Jeffreys to compare DNA profiles from different individuals.
What were the first uses of DNA fingerprinting technology
Was used in 1989 in England to identify a criminal
What is a DNA fingerprint?
a laboratory technique used to establish a link between biological evidence and a suspect in a criminal investigation. A DNA sample is taken from a crime scene and is compared with a DNA sample from a suspect
What is a DNA dragnet?
a dragnet is any system of coordinated measures for apprehending criminals or suspects. A DNA database or ‘random’ testing of suspects DNA
What is an RFLP?
restriction fragment length polymorphisms: RFLPs. They are variations found from individual to individual.
What sorts of changes to DNA result in restriction fragments that are different lengths?
PCR product length varies according to number of repeats included within the amplified DNA
o Extra copies of a repeat
o Presence of a transposon, ‘jumping gene
o SNPs in the restriction site
What are some examples of DNA markers?
o SNP: single nucleotide polymorphisms. Variation at single base pair in the DNA
o RFLP: restriction fragment length polymorphisms. A potential variation in individual to individual
o STR/VNTR: short tandem repeats (STRs, 2-9 base pairs)
What is a ‘Codis Panel’?
Much less than 1% actually about one millionth of the total DNA is examined with the CODIS panel
The CODIS panel focuses on 13 DNA regions with lots of variations within the population, there are many different alleles that can be easily distinguished based on fragment length differences in these regions; therefore each individual has 26 loci that can be examined
How are mitochondrial DNA sequences used in forensic investigations?
unique identifications are not possible using mtDNA analysis, however it is an excellent technique to use for obtaining info in cases where nuclear DNA analysis is not feasible
How are DNA profiles used for the identification of human remains?
A genealogical DNA test is used. A genealogical DNA test examines the nucleotides at specific locations on a person’s DNA for genetic genealogical purposes. This does not identify disorders or have informative medical value, it is solely intended to give genealogical information. They generally involve comparing the results to living individuals.
How is mitochondrial DNA used in genealogical tests?
tests the maternal inheritance, passed only from mother to children. Uses haplotypes (patterns of DNA markers and sequence differences) to trace maternal ancestry. Focuses on a region of several hundred base pairs that has the most variation.
How is the Y chromosome DNA used in genealogical tests?
The Y chromosome is passed only from father to son, so the Y haplotypes can be used only to trace paternal inheritance
