Forensics Exam 1
Human hair grows at an approximate rate of ____cm per month
1.3
______ was the first comparison microscope use (date)
1934
Hair analysis has been used since the ____ century
19th
Toxins found at 9 cm contains materials ingested ___________ ago.
7 months
True or false All hairs on the head of a person are identical
False
Securing the crime scene is the duty of the
First responder
____________principle: when a person comes into contact with an object or another person, a cross transfer of physical evidence can occur
Locard's exchange
What are the 7 "s" of CSI
Securing the crime scene, Separate witnesses, Scan the crime scene, see the crime scene, sketch the crime scene, search for evidence, secure evidence
_______________________________- 1910 study of microscopic images of human and animal hair (first known reference guide)
The hair of man and animals
True or False The shaft of the hair is considered class evidence in a trial
True
True or false Hair can provide clues about someone's ancestry
True
A characteristic of natural fibers is that they a. are affected by microscopic organisms b. will break down when exposed to bright light c. melt at a lower temperature than synthetic fibers d. are stronger than synthetic fibers
a
All of the following should appear on an evidence label except a. postmorten interval b. date, time c. name of collector d. case number
a
Human hair has which type of cuticle a. imbricate b. spinous c. coronal d. pigmented
a
Mineral fibers such as asbestos are very durable. These fibers have been used in all of the following except a. rope b. shingles c. floortiles d. brake linings
a
The type of weave pattern of a fabric affects all of the following except a. shiny appearance b. stretch of a fabric c. solubility in water d. strength of fabric
a
Which of the following is most likely a result of hair bleaching a. increased number of disulfide bonds b. oxidized hair and damaged DNA c. a more triangular cross section d. thickened scales on the cuticle
a
Class evidence narrows the evidence to:
a group of people
Individual evidence narrows the evidence to:
an individual
______________- group of plants in an area dominated by one species that share the same habitat requirements
assemblage
Although variations can occur, which of the following best describes European hair? a. kinky with dense, unevenly distributed pigment b. straight or wavy with evenly distributed granules c. round cross section with a large diameter d. coarse with a thick cuticle and a continuous medulla
b
Locard's Principle of exchange implies all of the following except a. Fibers can be transferred from one person to another b. Blood spatter can be used to identify blood type c. Cat hair can be transferred to your pants d. Soil samples can be carried from the yard into your home
b
Microscopic hair analysis a. yields individual evidence b. is used to exclude a suspect c. can prove a suspect's guilt d. can determine maternal inheritance
b
The period when hair is naturally shed is called the _____________ stage. a. catagen b. telogen c. anagen d.imagen
b
The shiny nature of silk can be related to a. its hollow core b. its ability to reflect light c. its smooth, round fibers d. mucus secretions from the silkworm
b
Which of the following characteristics is found in typical Asian hair? a. dark medulla b. sparsely distributed pigment granules c. flattened cross section d. curls
b
Diatoms a. are visible to the naked eye b. have a cell wall composed of rigid cellulose c. are found attached to rocks and plants in bodies of water d. are used to assist in crime scenes involving insects
c
The reason it is important to separate the witnesses at the crime scene is it a. prevent contamination of the evidence b. prevent fighting among the witnesses c. prevent the witnesses from talking to each other d. protect them from the perpetrator
c
What characteristics of cotton make it a great source of fiber for clothing a. its a polymer of keratin b. it is resistant to staining c. The fibers are easily woven and dyed d. The fibers are extremely long
c
Which factors are used to calculate the medullary index of the hair a. scale diameter of cuticle and the length of the hair b. width of cortex and the width of the medulla c. length of entire hair and the pattern of pigmentation d. width of medulla and the width of the hair
c
Plant fibers all share the same polymer: ____________
cellulose
Hair is considered _______ evidence.
class
Two Types of Circumstantial evidence:
class and Individual
In humans the _______ is the largest part of the hair shaft
cortex
_____________- region of the hair located outside the medulla that contains granules of pigment
cortex
seed fibers are typically used in:
cotton
________-tough outer covering of a hair that is composed of overlapping scales
cuticles
A crime-scene sketch should include all of the following except a. a distance scale b. date and location of the crime scene c. a north heading d. the type of search pattern used to collect the evidence
d
Animal hair can be distinguished from human hair because animal hair a. has a smaller medullary index than human hair and no cortex b. does not have a cuticle c. always has a continuous medulla pattern d. has a greater medullary index and more variation in the cuticle patterns
d
Botanical evidence is a valuable source of evidence because a. it is easily overlooked by perpetrators b. many plants have adaptations that make them easily transferred c. the collection of plants in an area can help identify an area d. all the above
d
Correct collection of evidence requires which of the following? a. documenting the location where the evidence was found b. correct packaging of evidence c. maintaining proper chain of custody d. all of the above
d
Hair can be used to determine a. diet b. drug habits c. geographic history d. all of the above
d
Natural fibers can be harvested from a. plants and animals b. only from plants c. only from animals d. plants. animals, and minerals
d
Which part(s) of a hair can be analyzed for nuclear DNA? a. follicle b. shaft c. medulla d. all of the above
d
Two types of evidence:
direct, circumstantial
True or False Hair is composed mostly of a protein called cellulose
false
Direct evidence is:
first hand accounts (weapon, video)
A datum point is a
fixed object (like a post or cement pillar)
____________-the actively growing base of a hair that contains DNA and living cells
hair follicle
________________-part of the hair above the follicle; contains mitochondrial DNA
hair shaft
What are three examples of evidence:
hair, fingerprints, fiber
stem fibers are typically used in
hemp
Circumstantial evidence is:
indirect evidence that can be used to imply, but not prove
What three things depend on the extent of the transfer of evidence?
intensity, duration, nature
What is triangulation?
mathmatical method to calculate the location of an object from the location of other objects
____________-the central core of the hair
medulla
______________- the ratio of the medulla to the diameter of the entire hair
medullary index
The cortex contains the most _________________.
melanin granules
___________-genetic material in the mitochondria of the cytoplasm of a cell (only inherited from mother)
mitochondrial DNA
polymers are long repeating _____________
molecules
Synthetic fibers are made from:
monomers
After securing evidence, what are the four things that need to happen to the evidence:
package, seal, catalog, chain of custody
________________-the study of pollen and spores
palynology
5 ways to differentiate between hairs
pigment, chemical, medullary index, medulla type, ethnicity
_________- the number and type of pollen grains found in a geographic area at a particular time of year
pollen fingerprint
Fibers are composed of ____________
polymers
____________-time elapsed between a person's death and discovery of the body
post-mortem interval
What are two reasons to separate witness's
prevent collusion, prevents contamination of direct evidence
Three things to look for when finding grave sites:
settling, new assemblage, unique plants
Five different types of medulla
solid, none, hollow, absent, fragmented
What are 3 technologies used when searching the crime scene for evidence?
sonar, black lights, radar
What are two purposes to sketching a crime scene
to note position of remains and where other evidence is
What is the 3 reasons to secure a crime scene
to protect it, prevent intrusions, prevent contamination
A greater number of fibers found on the victim could indicate a greater level of:
violence
Multiple locations of fibers on a victim could suggest two things:
violence, prolonged contact
What 4 things can you find while doing chemical testing on hair?
water, food, toxins, drugs
4 objects that are used to collect fiber evidence
tape, forceps, vacuum, lint roller