After The Midterm Flashcards
Blood serum is defined as:
the yellow colored watery fraction of clotted blood
What kind of cells do not contain nuclear DNA?
Mature red blood cells and Erythrocytes
Why are buccal swabs generally taken as known DNA samples instead of blood samples?
- Less invasive
- Require less training
- Easier to collect
- Easier to keep in stock
What type of packaging container is recommended for blood and biological fluid evidence?
Sealed paper bags
What test is used to confirm the presence of a bloodstain on an evidence item?
The Takayama Test
Luminol reagent reacts with blood in the presence of peroxide to emit light by a chemical process known as:
Chemiluminescence
What component of red blood cells is responsible for the peroxidase-like activity of blood:
Hemoglobin
What are considered blood confirmatory tests?
The Takayama Test and the Teichmann Test
Semen stains illuminated with UV light will emit light by a process called:
Fluorescence
T/F Leukocytes are the principle source of nuclear DNA in liquid blood.
True
T/F The only reason to conduct presumptive testing at a crime scene is to decide whether an item should be collected and submitted to the laboratory for examination.
True
T/F Blood stains often fluoresce brightly when exposed to UV light
False
T/F A confirmatory test for semen is called the Christmas Tree Stain
True
T/F A UV light should be used for search and examination purposes only and is not considered a presumptive test.
True
Define and explain the difference between blood serum and blood plasma.
Blood serum is a straw colored substance that is left behind after the blood clots.
Blood plasma is a straw colored substance that remains after the blood settles (or does not clot).
Define and give two examples each of a presumptive test and a confirmatory test.
Presumptive: done to see if a biological substance MAY be present.
Confirmatory: confirms that the substance is 100% there.
Examples:
Presumptive: Semen (Acid Phosphatase)
Saliva (Presence of Amylase)
Confirmatory:
Semen (Christmas tree stain)
Sperm (Prostate Specific Antigen)
List and briefly explain the three different categories of sexual assault investigations.
Unknown: adult v adult; unknown assailant
Known: adult v adult; known assailant; usually becomes a consent issue
Crime Against children: adult v child under the age of consent or more than 36 mo older than the victim
List and define two categories of control samples that can be collected and submitted to the lab.
Alternative Known Control: specimen obtained from a known source that might be the source of the evidence
Blank Control: clean sample containing no specimen that is used to ensure a test is working properly
What is the number range of sperm that may be present in 1mL of semen from a mature, fertile male?
15 mil - 80 mil
What color does semen appear when it fluoresces under UV light and what color filter is used to help visualize it?
Fluoresces blue-green under an orange filter
The principle narcotic drug found in opium is known as:
morphine
An analgesic is a drug which acts as a:
pain killer
Cocaine is classified as the following type of drug:
a stimulant
Drugs that cause marked alterations in normal thought processes, perceptions, and mood are classified as:
Hallucinogens
What drug acts like a depressant of the CNS?
Alcohol
Psilocin and psilocybin are naturally occurring hallucinogens that are found in:
a type of mushroom
The active ingredient of marijuana that is largely responsible for its hallucinogenic properties is known by its acronym:
THC
Drugs deemed to have the highest potential for abuse and have no currently accepted medical use are listed in which schedule of the Controlled Substances Act?
I
The Modified Duquenois Levine color test is a screening test for which drug?
Marijuana
What color would you expect to find on a positive Cobalt Thicynate test for cocaine?
Blue
T/F The Gold Chloride test is used as a confirmatory test for PCP
False
T/F Chromatography techniques are used to separate different components of a substance.
True
T/F The Federal Controlled Substances Act has six schedules of classification for drugs based on their accepted medical use and potential for abuse.
False
Ketamine has a legal use as an anesthetic and a tranquilizer.
True
Headaches that result from withholding caffeine are an example of a physiological dependence on caffeine.
True
Define and distinguish physiological and psychological dependence
Physiological: your body needs more of the drug to get the same effect that you used to get on a lower dosage
Psychological: when a person feels like they need to have the substance on hand all of the time.