1/508
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai |
|---|
No study sessions yet.
Which of the following best describes the value of field kits for chemical testing of controlled substances?
A. they remove the necessity for laboratory analysis
B. they are presumptive tests
C. they have questionable reliability
D. they allow the officer to make a field identification
They are presumptive tests
The primary reason for proving "chain of custody" on a particular item in court is to:
A. authenticate the item
B. Show how many people handled the item
C. Show how long it was in each person's possession
D. Deter or prevent unauthorized individuals from handling the evidence
authenticate the item
What is the highest energy in the spectral regions?
Ultraviolet
Human genomic DNA is not found in:
Red blood cells
You receive an envelope containing a semi-automatic pistol for an operability check. You open the envelope to examine the weapon. You first remove a fully loaded magazine. The weapon is now:
A. Potentially still loaded and unsafe
B. Unloaded and safe
C. Potentially still loaded but safe
D. Rendered safe because of a magazine disconnect
potentially still loaded and unsafe
When handling biological materials, which of the following is the most reasonable approach to take?
Precautions should be taken regardless of the condition or the origin of the samples being handled
Upon reviewing your notes for court appearance in one week, you realize that there is a clerical error and two results have been reversed. What is the best course of action?
Immediately notify the attorney and issue a report which makes the correction clear
Which of the following actions is not forbidden by the ABC Code of Professional Conduct?
A. Embellishing one's qualifications when testifying
B. Utilizing a secret weapon
C. Refusing to honor a subpoena duces tecum
D. Interpreting equivocal results based only on an employer's wishes
utilizing a secret weapon
A defendant has a combination of genetic marker types common to a particular evidence stain and 0.1% of the population. This means:
A. Approximately 1 out of 1000 people would have the same types
B. the next 999 people that walked into the court room would not have the same combination of types
C. we are 99.9% certain that the person responsible is being tried
D. we are 0.1% certain that the person responsible is being tried
approximately 1 out of 1000 people would have the same types
A drunk driver struck a pedestrian at a dark intersection. Realizing that the headlamps were not on, the driver turns them on before the police arrive. The broken right from low beam flashes and goes out. The police collect the headlamp and submit it to you for examination. You are likely to find which of the following indicators?
I. A sharp break
II. Hot deformation
III. Fused glass
IV. Large amounts of WO3 deposits
A. IV only
B. I only
C. II and III
D. II, III, and IV
I only (a sharp break)
What purpose does humidity serve when processing latent prints with Cyanoacrylate?
Causes polymerization and the formation of white particles on the ridges
What are the most important components of a Polymerase chain reaction?
oligonucleotides
Which one of the following statements applies to FT-IR but NOT dispersive IR?
A. the technique is considered to be a confirmatory test
B. the resulting spectrum is a measure of molecular vibration
C. the infrared radiation is analyzed utilizing interferometer
D. solid samples are prepared by mixing the sample with KBr and pressing a pellet
the infrared radiation is analyzed utilizing interferometer
The differences in striation markings along a gun's bore could be the result of:
A. imperfections of the rifling cutter, distortions caused by a broach cutter, and wear from the firing bullets over time
B. imperfections of the rifling cutter
C. distortions caused by a broach cutter
D. wear from the firing of bullets over time
imperfections of the rifling cutter, distortions caused by a broach cutter, and wear from the firing bullets over time
How will the Rf values of eluents most likely be affected if a TLC tank is not kept saturated with the developing solvent?
A. they will increase
B. they will decrease
C. they will increase or decrease unpredictably
D. they will not be affected
they will decrease
If the IR absorbance spectrum for a previously unidentified drug matches that of a l-amphetamine HCl standard, which of the following would be a justifiable conclusion?
A. the unknown is l-amphetamine hydrochloride
B. the unknown could be d-amphetamine hydrochloride
C. the unknown could be l-amphetamine sulfate
D. the unknown could be methamphetamine hydrochloride
the unknown is l-amphetamine hydrochloride
With which one of the following drugs will be the Marquis reagent NOT produce a colored reaction product?
A. morphine
B. mescaline
C. amphetamine
D. barbiturate
barbiturate
Which reagent would be most useful for visualization and differentiation of the various cannabinoid separated from a marijuana extracted on a TLC plate?
fast blue BB
The term "theoretical plate" refers to which one of the following parameters in gas chromatography?
A. retention time
B. polarity
C. efficiency
D. stationary phase thickness
efficiency
What is an MSDS?
a document of chemical safety
In microscopy, which one of the following terms describes the relationship between retardation and thickness?
A. aberration
B. dispersion
C. scattering
D. birefringence
birefringence
Ohm's law interrelate potential (volts) to:
resistance
What is the range of probabilities that two genes on the same chromosome will remain together after meiosis?
A. 5% to 25%
B. 1% to 99%
C. 25% to 75%
D. 50% to 99%
1% to 99%
A nucleic acid must contain a nitrogenous base and which of the following?
I. aromatic ring
II. 4 carbon ring
III. 3 carbon ring
IV. phosphate
A. I, II, and IV
B. III and IV
C. I and III
D. I and IV
III and IV (3 carbon ring and phosphate)
What are the four nucleotides found in DNA?
Cytosine, thymine, guanine, adenine
Which of the following factors DO NOT affect the migration of DNA fragments through an electrophoretic system?
I. pore size
II. tracking dye
III. DNA shape
A. II only
B. II and III
C. I and II
D. I and III
II only (tracking dye)
A three banded isoenzyme pattern with a 1:2:1 intensity ratio indicates a ____________ protein
A. monomeric
B. dimeric
C. trimeric
D. tetrameric
dimeric
What are organic compounds having the basic formula NH2-R-COOH (where R = an aliphatic or aromatic side chain) that are polymerized to form peptides and proteins termed?
A. amino acids
B. enzymes
C. phospholipids
D. polysaccharides
amino acids
Which one of the following products would be expected to contain the HIGHEST concentration of aromatic hydrocarbons?
A. paint thinner
B. gasoline
C. kerosene
D. coleman fuel
gasoline
The transfer of heat energy through a solid material by contact between its moving molecules is called:
conduction
Which of the following classes of compounds is the MOST indicative of gasonline?
A. polynuclear hydrocarbons
B. aliphatic hydrocarbons
C. alicyclic hydrocarbons
D. aromatic hydrocarbons
aromatic hydrocarbons
Which of the following garments would be the most suitable for collection of trace evidence by using a tape light technique?
A. nylon shell windbreaker
B. mohair sweater
C. cotton/polyester blend dress shirt
D. pair of blue denim trousers
nylon shell windbreaker
What is phaeomelanin?
a brown pigment occurring in hair
Which of the following is the most common type of esternal plasticizer found in the paint industry?
phthalates
Compared to glass jars or polyester bags, metal cans have what advantages for packaging and storing fire debris evidence?
easier to transport, resistance to corosion, more likely to survive long term storage intact, resistant to thermal stress during analysis
Which of the following are found in gasoline in significant quantities?
toluene, xylene, ethylbenzene
The lowest temperature at which a liquid gives off sufficient vapor to form an ignitable mixture with the air is called the
flash point
What is an indicator of an incendiary fire?
multiple points of origin
Unprocessed crude oil consists primarily of:
alkanes
When examining a paint chip what would support the conclusion that the chip is from an automobile that has been refinished?
five or more layers in the finish system
Refractive index can be defined as:
the ratio of velocity of light in a vacuum to that in any medium
Gas chromatography has the capability of separating mixtures on the basis of their distribution between:
a stationary liquid phase and a moving gas phase
What is the term describing chemical compounds that have the same chemical formula and the same bond arrangement, and differ only in the orientation of the molecules in 3D
isomers
A graying hair is often associated with:
an increase in diameter
What must be demonstrated by the Forensic Chemist to prove arson?
Willful Intent, Destroy the Dwelling of Another, and the Use of Fire
Reasons for Arson
Pyromania, Insurance Fraud, Heroism, Revenge, Terrorism, Vandalism, Cover up Crime
Ignition Temperature
minimum temperature at which a fuel will spontaneously ignite
Combustion
rapid combination of oxygen and fuel to produce noticeable heat and light
Exothermic reaction
reaction which liberates heat
Endothermic reaction
reaction which absorbs heat from environment
heat of combustion
heat evolved when a fuel is burned in oxygen
Essential Elements of Fire
fuel, air, heat, and propagation of Reaction
Types of Fires
Glowing and Burning
Glowing
ignitable fuel is exhausted, burns like charcoal, gives off tremendous heat but NO smoke, smoldering
Burning
flames present, fuel still being pyrolyzes, evidence of smoke
Fuels (States of Matter)
solid-liquid-gas
Fuel only burns in what state?
Gaseous state
Common Fuels
Gasoline, kerosene, charcoal lighter fluid, lighter fluids, solvents
What level of oxygen does the fire begin to get weak?
15%
Heat is a form of energy transferred through?
conduction (solids), convection (plasma), and radiant energy (IR)
Propagation of Reaction is...
self sustaining, oxidation reaction, and the reaction ends when cycle is broken
Point of Origin
where fire started, distinctive patterns may be present, use of portable sniffers (dogs and electronic devices)
Collection of Arson Evidence
place evidence into airtight containers (paint cans and polyester bags), collect control sample, clothing of suspect, look for igniters
Analysis of Arson Debris
heated headspace analysis, solvent extraction, dynamic adsorption, passive adsorption, pure substances
Alcohol percentages
Beer/Ale (4-6 and 5-8%), wines (12% natural, 22% fortified), liquor (40-55%)
Concentration Units
Percentage Alcohol, Proof, and BAC Units
Congeners
fusel oils, organic acids, esters, and acetaldehyde
Standard Drinks
12 oz of beer, 4 oz of wine, 1 oz 100-proof liquor
Factors affecting Oral Absorption of Ethanol
carbonated beverages enhance, fatty and oily beverages slow, ethanol concentration, higher altitudes promote absorption, presence of food in stomach delays
Routes of Alcohol Administration
Oral, Inhalation, Skin, Injection, Rectally
Water Content of Ethanol Distribution
the greater the water content, the greater the ethanol concentration relative to other tissues
Elimination of Alcohol
Metabolism (95+% via Liver), Direct Excretion (5% through breath, urine, and perspiration)
CNS Depression
Impaired judgement, depressed learned social and cultural inhibitions, impaired self-evaluation, euphoria, memory loss, shortened attention span
Stage I of Alcohol Influence
Affects frontal portion (memory and judgement)
Stage II of Alcohol Influence
Equilibrium, muscular coordination, senses
Stage III of Alcohol Influence
Autotomic Nervous System
Tolerance
effect which results from the chronic use of a drug where a larger dose becomes necessary to achieve the effect
Acquired Tolerance
results from the chronic use of alcohol; individuals are still impaired in judgement, reaction and coordination
Metabolic Tolerance
Biochemical changes which affect the rate of metabolism and elimination from the body
Melanie Effect
acute tolerance of ethanol; an individual perceives himself as less impaired at a given alcohol concentration in the elimination phase than at the same concentration of the absorption phase
Physical Deficits produced by Alcohol
alter distance perception, impaired hearing, reduced muscular coordination, increased reaction time, blurred vision, and nystagmus
Henry's Law
the weight of any gas that dissolves in a definite volume of liquid is directly proportional to the vapor pressure exerted above the liquid
Charles' Law
the volume of gas varies directly with the Kelvin temperature
Alveolar Air Sample
alveolar air sacs are the only area in the lung that are in direct contact with blood supply
Intoximeter
based on infrared absorption, amount of absorption is proportional to amount of alcohol
DNA stands for...
Deoxyribonucleic Acid
DNA is...
the genetic blueprint that makes us unique; only 1% is different from one another
'Bases' of DNA
A, T, C, and G; A pairs with T, and C pairs with G
Inheritance
23 pairs of chromosomes (2 copies of each pair)
With serology, a larger size and better quality uses
RFLP (Restriction Fragment Length Polymorphism)
With serology, a smaller size and poorer quality uses
PCR (Polymerase Chain Reaction)
RFLP (Restriction Fragment Length Polymorphism)
Takes long strands of DNA and cuts them up into smaller fragments
PCR (Polymerase Chain Reaction)
Makes copies of small/degraded DNA samples until there is enough to test; not as varied as RFLP; focuses on several locations of DNA that differ in sequence between people
First step of RFLP
-Extraction
-Cleansing and purifying the sample from serology
-Final product in long strands of high quality, purified DNA
'Restriction' of RFLP
cutting up the DNA into smaller fragments; accomplished using chemical scissors that cut specific sequence along the DNA; the length of the DNA differs and we can distinguish between them because people have different lengths based on repeated areas of DNA
Electrophoresis
applying an electric current across the gel in order to separate pieces based on lengths from RFLP by placing them in gel
Denaturation
making DNA single-stranded for later testing
"Southern Blot"
"wicking" process that moves the DNA from the gel to the membrane
DNA Probing
use of labeling known DNA fragments to find a particular DNA sequence in a large collection
Probe
short segment of synthetic 'tagged' DNA used to detect a particular DNA fragment