Forensics Midterm Review Ch.7 DNA Profiling

DNA

deoxyribonucleic acid

Who has the exact same DNA

Identical twins

All cells, besides this one, contain DNA

Red Blood Cells

Nitrogen bases of DNA

Adenine, Thymine, Guanine, Cytosine

Be able to looks at a strand of DNA and find its complementary strand

Exons

The codings regions of DNA, they are expressed during protein synthesis

Genes

The basic unit of heredity

Alleles

The gene differences (the variable form of a gene)

Locus

An alleles location on a chromosome

Homozygous

An organism that has two identical alleles for a trait

homozygous dominant

AA

homozygous recessive

aa

Heterozygous

Aa

PCR

The process that copies and amplifies DNA samples for testing

Short Tandem Repeats (STR)

-Method of analyzing variable regions of DNA sequences

Where are STRs located

Found at specific locations on chromosomes called markers

How many STR markers does the FBI use for the identification of Americans

13 core STR markers

How do you know which STR markers repeats the most

The one with the biggest number

Ex: 34,24

How do you tell which STR is homozygous

The STR only has one number

Be able to read an STR graph

Study the Earthquake Victim assignment

An aunt and a nephew share ___________ of their DNA

25%

Why do forensics scientists typically use the number of STRs that they do when making claims of identification

It is possible for STR matches to occur by chance

Sometimes only by looking at more loci is it possible to determine the whether a victim is a relative