Deck 11: Hairs and Fibers

Question 1

Mohair and cashmere are hairs from:

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

Answer 1

A

Question 2

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 2

C

Question 3

By far the most prevalent plant fiber is:

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

Answer 3

D

Question 4

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

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

Question 5

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 6

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 7

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

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

Question 8

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

Question 9

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 10

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 11

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 12

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

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

Question 13

Medullae may be classified as being:

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

Question 14

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

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

Question 15

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 16

The conviction of Ennis Cosby's killer was aided by the DNA analysis on a hair that was crucial evidence in the case.This hair:

A) Belonged to Cosby and was found in the suspect's car.
B) Belonged to the killer and was found in his cap with which he had wrapped the murder weapon before discarding it.
C) Belonged to Cosby and was found clinging to the murderer's jacket.
D) Belonged to the killer and was found on the body of the victim.

Question 17

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

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

Question 18

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

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

Question 19

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 20

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 than
C) Greater than
D) None of the above

Question 21

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 22

In the collection of 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 23

The monomers involved in the synthesis of proteins are:

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

Question 24

The rate of human hair growth per month is:

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

Question 25

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 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 26

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 27

Which was the first man-made fiber?

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

Question 28

A regenerated fiber can be derived from:

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

Question 29

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 30

Which is NOT a synthetic fiber?

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

Question 31

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 32

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 33

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 34

Cellulose is the basic component of:

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

Question 35

Which is made of natural polymers?

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

Question 36

Before the 20th century,all fibers were:

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

Question 37

Which would produce "fingerprints" of the fibers?

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 38

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 39

The portion of the hair containing its scales is:

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

Question 40

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 41

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 42

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

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

Question 43

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 44

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

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

Question 45

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

Question 46

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

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

Question 47

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 48

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 49

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 50

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

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

Question 51

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

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

Question 52

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) 50; 25
B) 100; 100
C) 20; 20
D) 5; 16

Question 53

Rayon is classified as a:

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

Question 54

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 55

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

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

Question 56

Synthetic fibers display ________ because they are crystalline.

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

Question 57

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

Question 58

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 59

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 Caucasian or Negroid hair

Question 60

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

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

Question 61

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

Question 62

Hair is an appendage of the skin that grows out of an organ known as the hair ________.

Question 63

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

Question 64

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

Question 65

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

Question 66

It is not possible to link a fibers strand definitively to a single garment.

Question 67

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

Question 68

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

Question 69

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

Question 70

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

Question 71

One feature that makes hair a good subject for establishing individual identity is its resistance to chemical ________.

Question 72

The criminalist typically has many fibers available for analysis.

Question 73

Most animals have medullae that are either continuous or interrupted.

Question 74

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

Question 75

It is common to obtain a physical match for fibers.

Question 76

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

Question 77

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

Question 78

The scale pattern of the cuticle is an important feature for characterizing ________ hair.

Question 79

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

Question 80

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