Forensics Quiz: Ch 11 - Hair & Fibers
Terms in this set (118)
Hair is ____ in comparison with other physiological materials (blood, semen, fluids)
hair is strongly resistant from...
corroborate evidence, denote physical contact between perp & victim, possibly be an identifier
if properly collected, hair can ... if there is enough physical evidence
color, length, diameter
criminalistics/forensics is interested in the ... of hair
cuticle, cortex, medulla
3 parts of hair structure
scale structure covering exterior of hair folicle
individualizing and provide species identification
cuticle can be useful for..
human scale pattern
not easily observable under a mount
cuticle consists of..
hard overlapping scales that point towards the tip
main body of hair shaft
cortex contains .. which gives hair its color
dyed or bleached
microscopic examination of cortex can tell if hair has been ...
what does bleaching hair do to cortex ?
cellular column running the length of hair
present of absent
hollow tube within the hair within the hair may be ...
continuous, fragmented, or missing
medulla may be ... depending on the hair
human or animal
medullary index helps forensics scientists differentiate between
less than 1/3
human medullary index
1/2 or greater
animal medullary index
diameter of medulla ÷ diameter of the hair =
presence of medulla
important feature of medullary index is...
where does hair grow from?
anagen, catagen, telogen
3 phases of hair growth
initials phase of hair
root hair bulb-like appearance
has follicular tag
tissues surrounding root that has a rich DNA source
how long anagen phase last?
hair falls out or sheds naturally
root has club-like appearance
root has elongated appearance
person of caucasian origin (white people)
fine to medium coarseness
coarseness of Caucasoid hair
blonde, brown, red, black
common hair colors of Caucasoid
round to oval
cross sectional of Caucasoid
fine to medium; evenly distributed
pigment granules of Caucasoid
continuous, fragmented, absent
person of asian decent/origin
regular; straight coarseness
coarseness of Mongoloid hair
black to dark brown
hair color of mongoloid
cross sectionals of mongoloid
which race has widest diameter?
which race has the the thickest cuticle?
continuous and wide
person of African origin
regular, curly, kinky coarseness
coarseness of negroid hair
cross sectionals of negroid
larger than other races, grouped in clumps, different sizes, and shapes
pigment granules of negroid
hair with little diameter variation, uniform pigmentation
short and curly hair with wide variation diameter
coarse hair with blunt tips and are triangular cross sections
what does hair with follicular tag have?
DNA that is only genetically passed from mother to child
individuals with maternal link
what can mitochondrial DNA determine ?
how many scalp hairs are needed for evidence?
how many pubic hairs are needed for evidence?
synthetic and natural
categories of fibers
hit & run, breaking & entering
crimes in which fibers could be viable evidence
mohair, cashmere, wool, camel hair, llama hair, alpaca hair
first synthetic fiber manufactured
nylon (acetate; 1939)
second synthetic fiber manufactured
regenerated from cellulose
natural machine made fibers
starts from chemicals
synthetic machine made fibers
produces raw materials derived from corona and wood pulp
extracted through chemical treatment or a dissolving method then forced through small holes
fabrics that can be fitted together at torn edges that provide almost certainty of common origin
color and diameter
first thing measured under microscope
what do forensic analyst use for spectral line comparison
chromatic separation of dye will give...
what kind of surfaces does manufactured synthetics have?
"child murders" case (1981)
29 African American men in Atlanta
how many people are thought to have been murdered by Wayne Williams
2 of 29 suspected
how many cases was Wayne Williams convicted of?
how many fibers from Wayne Williams' home and car were matched to victims?
what is most important for individualization?
most prevalent plant fiber
T or F: it is possible to identify hair through morphology
places person at scene
what is the purpose of hair being present?
refractive index and ultra violet lighting
is used for close examination of hair/fibers unaided eye cant see
what is hair?
what organ produces hair?
medulla, cortex, cuticle
3 layers of hair
animal or human hair
what does scale pattern of hair help determine?
what cannot be determined by hair under microscope?
pubic and head
what parts of the body are the body are hair taken from for investigation?
why was central park jogger case acquited?
what is fiber called when it comes through spinneret?
what is dan called that comes from both parents?
cross sectionals and pigment granules
how can you tell hair is from a specific race
what fiber is used for bullet proof vest
what is made from natural polymers?
mo hair and cashmere
what fabric comes from goats?
basic unit for fabric
average amount of hair growth in 1 month
what part of hair is color found in?
what shapes are beard cross sectionals?
T of F: all polymers are synthetic
what does chromatography test?
what is called when manufactured fibers exhibit double refraction?
what evidence was prominent evidence for telltale rabbit case
hair is an appendage of the skin growing out of scalp known as...
central canal running through many hairs is called...
uniserial and amorphous
multiserial and lattice
uniserial, multiserial, vacuolated, lattice, and amorphous
forensic hair hair patterns
coronal, imbricate, spinous
hair cuticle patterns
coronal and spinous
animal hair cuticle patterns
human hair cuticle pattern
simple, serrate, and dentate
types of coronal scales
crenate and flattened
types of imbricate scales
without shape; uniserial