Forensics: chapter 3 review
false
All hairs on the head of a person are identical
straight with evenly distributed granules
Although variations can occur, which of the following best describes northern European hair?
· hair consists of a FOLLICLE embedded in the skin that produces the shaft · the shaft is composed of the outer CUTICLE, a CORTEX, and an inner MEDULLA. · The MEDULLA is the central core. · The CORTEX is the area outside the medulla and contains pigment granules. · The CUTICLE is the tough outer coating with layers of scales. · Each of these varies among individuals and species.
Describe the structure of hair. Include in your answer the terms follicle - medulla - cortex - cuticle
false
Hair is composed of a protein called cellulose
imbricate
Human hair has which type of cuticle?
silver
Neutron activation analysis can check hair for the presence of.....
true
The cortex may contain pigment granules
tip of the hair
The cuticle scales of the hair always point toward the.......
medulla
The hair shaft is composed of the cuticle, cortex and.......
anagen stage
The period of active hair growth is called
width of medulla and width of hair
Which factors are used to calculate the medullary index of the hair?
dark medulla
Which of the following characteristics is found in typical Asian hair?
a yellowish tint to the hair
Which of the following is most likely a result of hair bleaching?
root or the follicle
Which part(s) of a hair can be analyzed for DNA?
· Class evidence is a material that connects an individual or thing to a certain group · Hair cannot be used to identify a specific individual because only a group of people share a similar type of hair.
Why is hair considered class evidence?
comparison microscope
a compound microscope that allows the side-by-side comparison of samples, such as of hair or fibers
individual evidence
a kind of evidence that identifies a particular person or thing
neutron activation analysis
a method of analysis that determines composition of elements in a sample
cortex
area outside the medulla and contains pigment granules.
melanin granules
bits of pigment found in the cortex of a hair
human hair has a smaller medulla human hair index is .33, animal hair index is .50 or greater anima hair has a denser pattern of pigmentation humans have an imbricate cuticle
describe the difference between human and animal hair
follicle
hair consists of a ______embedded in the skin that produces the shaft
the ratio of the diameter of the medulla to the diameter of the entire hair
how do you calculate the medullary index for a hair?
the hair follicle is present
how do you know if a hair was forcibly removed from a victim?
class evidence
material that connects an individual or thing to a certain group
trace evidence
small but measurable amounts of physical or biological material found at a crime scene
cortex
the region of a hair located outside of the medulla containing granules of pigment
cuticle, cortex, and an inner medulla
the shaft is composed of what 3 things?
cuticle
the tough outer covering of a hair composed of overlapping scales
true
true/false: The shaft of the hair is considered class evidence in a trial
cortex
what is the largest part of the hair shaft?
medulla indez
what is the ratio of the diameter of the medulla over the diameter of the whole hair
imbricate
what type of cuticle does human hair have?
· Human hair has a smaller medulla; humans less than .33 index, animals have .50 or greater index. · Animal hair has a DENSER PATTERN OF PIGMENTATION · Humans have an IMBRICATE Cuticle type
Crime-scene investigators collected hair from a dead person's body. One of the first things that needs to be established is if this hair is human or animal. Describe two ways that animal hair differs from human hair.
keratin
a type of fibrous protein that makes up the majority of the cortex of a hair
scales point to the tip
which direction do the scales point?
hair follicle
the actively growing root or base of a hair containing DNA and living cells
medulla
the central core of a hair fiber
