Is it possible for two people to have the same DNA? How?
Yes, identical twins
15
Forensic biologists compare DNA samples by looking at how many markers?
13
15
The PCR technique:
makes millions of copies of the DNA markers
25
The four steps of DNA processing are:
Extract, Amplify, Separate, Analyze
25
Vitreous humor is found in the:
eye
15
What does SCREENING test accomplish?
checks for the presence or absence of chemicals
20
What happens to a chemical when it is analyzed by the Gas Chromatography/Mass Spectrometer (GC/MS)?
It is broken into fragments which are each counted to create a graph
25
A mass spectrum of a chemical:
will be unique, unlike the mass spectrum of any other chemicals
25
How do CSIs ensure that evidence does not get tampered with?
Anytime someone examines evidence, they must sign a Chain of Custody form
25
What is a positive control?
a sample prepared by the toxicologist which has a specific chemical present
25
The _______marks the bullet with the gun’s unique characteristics.
Rifling
15
What is the caliber of this bullet?
9mm
15
Where do investigators test fire a suspected gun in order to get individual characteristics of the gun?
in a water tank
15
What equipment do investigators use to analyze striations on bullets?
Comparison microscope
20
A 9mm bullet was collected from the victim, and two firearms were found at the crime scene. Both gun 1 and gun 2 use 9mm bullets. How can the investigators determine which gun fired the bullet?
Test fire the suspected guns and compare the bullet striations to the fatal bullet.
