Chapter 9: DNA typing

amplicons

product of amplification of DNA or RNA

annealing

pairing of complementary strands of dot-blot DNA analysis (DQ-alpha and amplitype PM)

base pairs (bp)

Combination of two nucleotides (A and T or G and C) held together by weak hydrogen bonds. The DNA double helix is formed when base pair nucleotides in the DNA strands are connected by these bonds. The DNA strands are held together by strong chemical bonds. The two halves of the molecule are held by the weaker hydrogen bonds. The double helix may be visualized as two strips of Velcro. Weak bonds hold it together and the two strips are difficult to break or rip.

capillary electrophoresis

an instrumental technique that is used in DNA typing

colin pitchfork

first man convicted of a crime as a result of DNA testing

denaturation

loss of natural configuration of a molecule through heat, chemical treatment, or pH change

DNA polymerases

enzymes that break the linkage within the double helix of DNA

flanking region

region just adjacent to a region of interest, a gene, a repeat, or any other sequence

heterozygosity

two different alleles at a specific genetic locus

homozygous

refers to both alleles being the same at a specific genetic locus

hypervariable regions

locus with many alleles, especially those whose variation is due to variable numbers of tandem repeats

kary mullis

biochemist who invented PCR

laser-induced fluorescence (LIF)

detection method used in capillary electrophoresis method of DNA typing

maternal lineage

genetic component passed through the female lines of a family (mitochondrial DNA)

microsatellites

short tandem repeat or simple sequence length polymorphisms composed of di-, tri-, tetra-, or pentanucleotide repeats

minisatellites

simple sequence tandem repeat polymorphism in which the core repeat unit is usually 10 to 50 nucleotides long; variable number of tandem repeats

mitochondria

energy-producing structure within a cell that contains DNA called mitochondrial DNA/ mtDNA (not the same as nuclear DNA)

nucleases

enzymes that break down DNA

nucleotides

molecule consisting of a base, a pentose sugar, and a phosphoric acid group

polymerase chain reaction (PCR)

reaction used to make copies of segments of DNA

satellite DNA

Highly repetitive eukaryotic DNA located primarily around centromeres and found in other places in the genome. The buoyant density of it is usually different from that of the other DNA of a cell. The repetitive DNA forms a satellite or off-the-bell-curve fraction in a density gradient because of the base compositions of the repetitive regions.

short tandem repeats (STRs)

a simple, short sequence of DNA that contains a repeated pattern of A,T,C, and G

Sir Alec Jeffreys

first scientist to perform DNA analysis in a forensic case

tetramers

repeats of four base pairs

variable number tandem repeats (VNTRs)

Chromosomal locus at which a particular repetitive sequence is present in different numbers in different individuals of a population; a simple sequence tandem repeat polymorphism in which the core repeat unit is usually 250 bases long.

inside the nucleus

Where in the cell is DNA located?

WBCs, muscle cells, skin cells, hair cells, nerve cells

Name three types of human cells that contain DNA.

they published the double helix model

What was the contribution of Watson & Crick to the understanding of DNA?

allow state and local crime laboratories to store and compare DNA profiles from crime-scene evidence and convicted offenders

What is the purpose of CODIS?

it allows for trace amounts of DNA to be multiplied and analyzed, as well as for DNA to be multiplied to an amount that can be divided between analysts & investigators

Why is PCR important in DNA analysis?

in the hair follicle

Where is mitochondrial DNA located in the body?

denature, anneal, elongate

Describe the process of PCR.

Sir Alec Jeffreys

Who was the first scientist to use RFLP in a forensic case?

microsatellites

Which of the following is a class of repetitive DNA: structural genes, microsatellites, operator genes, homologous genes, or siRNA?

translation

Which of the following is not a step of PCR: denaturation, lysis, polymerization, annealing, translation?