Deck 11: Hairs and Fibers

Question 1

The medullary index of human hair is ________ the medullary index for most other animals.

A)The same as
B)Less than
C)Greater than
D)None of the above

Answer 1

B

Question 2

Pigment granules that impart hair with color are found in the:

A)Cortex.
B)Medulla.
C)Cuticle.
D)Both A and B

Answer 2

A

Question 3

The number of hair scales pointing towards the tip of the hair is ________ the number of hair scales pointing towards the hair follicle.

A)The same as
B)Less than
C)Greater than
D)None of the above

Answer 3

C

Question 4

Which of the following is NOT a layer of the hair shaft?

A)Cuticle
B)Cortex
C)Medulla
D)Follicle

Question 5

Medullae may be classified as being:

A)Interrupted or absent.
B)Fragmented.
C)Continuous.
D)All of the above

Question 6

Which part of the hair shaft is most resistant to chemical decomposition?

A)Cortex
B)Medulla
C)Follicle
D)Cuticle

Question 7

Which race is most likely to have head hair with continuous medullae?

A)Negroid
B)Caucasian
C)Mongoloid
D)Native American

Question 8

The central canal running through many hairs is known as the:

A)Shaft.
B)Medulla.
C)Cuticle.
D)Cortex.

Question 9

Which feature of hair is MOST important in making a species identification?

A)Follicle shape
B)Scale pattern
C)Bulb size
D)Shaft length

Question 10

In determining whether a hair sample originated from a male or a female, the MOST important consideration is:

A)Whether the hair is bleached.
B)The results of DNA analysis performed on the root structure.
C)Whether the hair was dyed.
D)The length of the hair.

Question 11

Describe the process of floatation and explain what it is used for.

Question 12

What is a physical property? What is a chemical property? Name one physical and chemical property of water.

Question 13

A storefront window is broken and a robbery committed. A suspect is later found running from the scene. Examination of his shoes reveals glass particles embedded in a heel. Describe the proper collection and preservation of glass evidence for laboratory examination.

Question 14

What physical properties are used most often to characterize glass particles? What is the main drawback of using these properties to characterize glass?

Question 15

A criminalist is attempting to find the side of a glass pane from which a shattering force originated. How can that be determined when examining a fragment from a radial crack? A concentric crack?

Question 16

What two models do scientists use to explain the nature of light? Under what conditions does each model best describe the behavior of light?

Question 17

A human hair in cross-section appeared flat in shape. The racial origin was most likely:

A)Caucasian.
B)Negroid.
C)Indian.
D)Mongoloid.

Question 18

A cast of a hair surface can be made using:

A)An SEM.
B)Clear nail polish.
C)Softened vinyl.
D)Both B and C

Question 19

Beard hairs are coarse and normally ________ in cross-section.

A)Ribbon-like
B)Oval
C)Triangular
D)Round

Question 20

What is refraction? How does the refractive index of a medium affect what the viewer observes when looking at the medium?

Question 21

A regenerated fiber can be derived from:

A)Polyester.
B)Cellulose.
C)Rayon.
D)Acetate.

Question 22

If a hair does not have a follicular tag, an expert witness is on best scientific footing when stating that:

A)The hair in question comes from a 21-year-old.
B)His/her examination reveals that the hair is that of a male.
C)The given hair comes from a specific person.
D)A suspect hair comes from a particular animal species.

Question 23

The presence of sheath cells on hair that has been pulled quickly from the head is ________ the presence of sheath cells on hairs that have been removed slowly from the scalp.

A)The same as
B)Less likely than
C)More likely than
D)None of the above

Question 24

Before the 20th century, all fibers were:

A)Natural.
B)Regenerated.
C)Synthetic.
D)Derived.

Question 25

Which would involve determining the refractive index of the fibers?

A)Microscopic examination for color and diameter of fibers
B)Infrared spectrophotometry
C)Study of the birefringence of the fibers
D)TLC study of dyes in fibers

Question 26

When collecting fiber evidence, great care should be taken to:

A)Avoid cross-contamination of evidence.
B)Shake off all garments to be sent for examination before neatly folding them.
C)Send as much potential evidence as possible to the crime lab to ensure that nothing is missed.
D)Package all items from each individual together in one bag to avoid later confusion.

Question 27

Which is NOT a synthetic fiber?

A)Rayon
B)Polyester
C)Acrylic
D)All of the above are synthetic

Question 28

What was the first man-made fiber?

A)Nylon
B)Polyester
C)Acetate
D)Rayon

Question 29

The visible light microspectrophotometer is a convenient tool with which to compare the color of fibers because:

A)Very small samples can be compared.
B)Fibers can be studied right on a microscope slide.
C)Fibers are not destroyed.
D)All of the above

Question 30

Nuclear DNA typing can be most successfully accomplished on hairs that have been removed during which stage of growth?

A)Telogenic
B)Mutagenic
C)Catagenic
D)Anagenic

Question 31

Which is made of natural polymers?

A)Plastic
B)Nylon
C)Starch
D)Paint

Question 32

By far the most prevalent plant fiber is:

A)Linen.
B)Silk.
C)Kapok.
D)Cotton.

Question 33

Which step in the examination of fibers would logically be taken first?

A)Examination of dye composition using visible light microspectrophotometer
B)Make a cross-sectional view of the fibers
C)Microscopic examination for color and diameter of fibers
D)Infrared spectrophotometry

Question 34

Mohair and cashmere are hairs from:

A)A goat.
B)A llama.
C)A sheep.
D)A camel.

Question 35

Which would produce "fingerprints" of the fibers?

A)Examination of dye composition using a visible light microspectrophotometer
B)Make a cross-sectional view of the fibers
C)Microscopic examination for color and diameter of fibers
D)Infrared spectrophotometry

Question 36

What is the rate of human hair growth per month?

A)1 inch
B)1 mL
C)1 cm
D)1 dm

Question 37

Which type of crime is LEAST likely to be solved with the use of fiber evidence?

A)Breaking and entering
B)Sexual assault
C)Bombing
D)Hit-and-run

Question 38

A fiber whose microscopic appearance includes being ribbon-like in shape (flat)with twists at irregular intervals is:

A)Polyester.
B)Cotton.
C)Kapok.
D)Linen.

Question 39

Generally, the parallel refractive index of a fiber is ________ the perpendicular refractive index of the same fiber.

A)The same as
B)Less than
C)Greater than
D)None of the above

Question 40

It is a virtual certainty that two fabrics share a common origin if their fibers:

A)Can be fitted together at their torn edges.
B)Have the same striations.
C)Have the same color.
D)Appear identical in cross-section.

Question 41

Rayon is classified as a:

A)Natural fiber.
B)Synthetic fiber.
C)Plant fiber.
D)Regenerated fiber.

Question 42

Which of the following properties should be examined when comparing two fibers?

A)Color
B)Diameter
C)Birefringence
D)All of the above

Question 43

The layers of the hair shaft are the ________, the ________, and the ________.

A)Cuticle; root; medulla
B)Cortex; mitochondria; pigment
C)Pigment; cortex; pigment
D)Cuticle; cortex; medulla

Question 44

The stages of hair growth include all of the following EXCEPT:

A)Anagenic.
B)Catagenic.
C)Telogenic.
D)Analgesic.

Question 45

Synthetic fibers display ________ because they are crystalline.

A)High density
B)Infrared reflectance
C)Dispersive properties
D)Birefringence

Question 46

For standard/reference hair sampling from a victim, the collection of a minimum of ________ full-length head hairs and ________ full-length pubic hairs is recommended.

A)25; 25
B)100; 100
C)20; 20
D)5; 16

Question 47

A hair sample was examined and its medulla appeared to have a pattern described as resembling a string of pearls. It was most likely from a:

A)Rabbit.
B)Deer.
C)Cat.
D)Mouse.

Question 48

In making hair evaluations, it is best to view the hairs using a(n)________ microscope.

A)Scanning electron
B)Comparison
C)Stereoscopic
D)Polarizing

Question 49

The monomers involved in the synthesis of proteins are:

A)Sugars.
B)Amino acids.
C)Fatty acids.
D)Starches.

Question 50

Forcibly removed hairs are most likely to provide useful DNA evidence because they bear:

A)Catagenic roots.
B)Telogenic roots.
C)Follicular tissue.
D)Mitochondria.

Question 51

Hair can best be characterized as originating from an animal by examining:

A)The medulla.
B)The cuticle.
C)Both the medulla and cuticle.
D)Its color.

Question 52

Which of the following properties should NOT be examined when comparing two synthetic fibers?

A)Presence or absence of delustering particles
B)Diameter
C)Lengthwise striations
D)Medullary index

Question 53

The cortex of hair derives its major forensic importance from the fact that it contains:

A)Scales.
B)Pigments.
C)Medullae.
D)DNA.

Question 54

In what stage can a hair most readily be removed from the scalp?

A)Anagenic
B)Catagenic
C)Telogenic
D)Analgesic

Question 55

Cellulose is the basic component of:

A)Sugar.
B)Starch.
C)Wood.
D)Wool.

Question 56

Microscopic hair comparisons must be regarded by police and courts as:

A)Conclusive.
B)Individualizing.
C)Useless.
D)Presumptive.

Question 57

Which statement is true?

A)The racial origin of hair can always be identified.
B)Hair can be individualized through its trace elemental composition.
C)Hair is routinely examined to determine sex.
D)Two hairs from the same head may not have the same morphological characteristics.

Question 58

A human head hair is best characterized by:

A)The absence of a cortex.
B)Its scale pattern.
C)A medulla that is more than 1/2 the overall diameter of the hair shaft.
D)A medulla that is absent or is less than 1/3 the overall diameter of the hair shaft.

Question 59

A criminalist is more likely to obtain DNA from hairs in the:

A)Anagenic stage.
B)Catagenic stage.
C)Telogenic stage.
D)Terminal stage.

Question 60

The portion of the hair containing its scales is:

A)The cortex.
B)The cuticle.
C)The medulla.
D)The root.

Question 61

The criminalist typically has many fibers available for analysis.

Question 62

Which of the following questions CANNOT be answered with a microscopic examination of hair?

A)Whether a hair came from a 25-year-old or an infant
B)Whether a hair is from a man or a woman
C)Whether a hair is from a scalp or a beard
D)Whether the hair is consistent with Mongoloid or Negroid hair

Question 63

A criminalist is most likely to collect DNA from hairs in the catagen stage.

Question 64

It is common to obtain a physical match for fibers.

Question 65

A microscopic examination can tell whether a hair is from a man or a woman.

Question 66

Members of the Negroid race usually have head hairs with continuous medullae.

Question 67

Manufactured fibers have increasingly replaced natural fibers in garments and fabrics.

Question 68

Forcibly removed hairs are most likely to provide useful DNA evidence.

Question 69

The scale pattern is not a useful characteristic for individualizing a human hair.

Question 70

Much of a hair's resistance and stability is attributed to the cuticle.

Question 71

Most animals have medullae that are either continuous or interrupted.

Question 72

The scale pattern of the cortex is an important feature for characterizing animal hair.

Question 73

A microscopic examination can tell whether a hair is from a scalp or a beard.

Question 74

The entire hair is collected because a hair may show variation in color and other morphological features over its entire length.

Question 75

Which of the following is NOT an example of a natural polymer?

A)Starch
B)Cellulose
C)Sugar
D)Proteins

Question 76

It is not necessary for questioned and standard/reference hairs to come from the same area of the body.

Question 77

Hair tends to exhibit variable morphological characteristics, not only from one person to another but also within a single individual.

Question 78

The cortex derives its major forensic importance from the fact that it gives hair its color.

Question 79

Finding white cotton fibers at a crime scene is nearly meaningless due to its wide use.

Question 80

The cuticle is formed by overlapping scales that always point away from the tip end of each hair.