Hair Analysis

Question 1

Why can hair be considered both class and individual evidence?

Answer 1

Individual evidence can be derived if the follicle were intact and nuclear DNA could be retrieved from it.

hair can yield class evidence (related to hair Ancestry).

Question 2

What is gas chromatography?

Answer 2

A method of separating chemicals to establish their quantities

Question 3

What can be revealed about an individual if chemical tests are performed on hair?

Answer 3

It can reveal drugs, toxins, heavy metals and nutritional definiens.

Question 4

What is nuclear DNA?

Answer 4

Genetic material in nucleus DNA.

Question 5

What is mitochondrial DNA?

Answer 5

Genetic material in the mitochondria of the cytoplasm; only inherited from the mother

Question 6

What are the several functions of hair?

Answer 6

regulates body temperature, decrease friction, protects against sunlight, acts as a sense organ

Question 7

What are the two basic structures of human hair?

Answer 7

A follicle and a shaft

Question 8

Where is the hair shaft?

Answer 8

The visable part of the hair that sticks out of the skin.

Question 9

Where is the hair follicle?

Answer 9

is underneath the skin

Question 10

What is hair composed of?

Answer 10

keratin

Question 11

What are the three main components of the hair shaft?

Answer 11

Cortex, Cuticle, Medulla

Question 12

what is the cortex?

Answer 12

The region of the hair located outside the medulla that contains granules of pigments

Question 13

What is the cuticle?

Answer 13

the tough outer covering of a hair that is composed of overlapping scales.

Question 14

What is the Medulla?

Answer 14

the central core of a hair.

Question 15

What are melanin granules?

Answer 15

Particles of pigment found in the cortex of the hair

Question 16

What are the five types of medulla?

Answer 16

Continuous, Interrupted, fragmented, Solid, None

Question 17

What is continuous Medulla?

Answer 17

one unbroken line of color

Question 18

What is fragmented Medulla?

Answer 18

Pigment line is unevenly spaced

Question 19

What is interrupted Medulla?

Answer 19

Pigment line broken at regular intervals

Question 20

what is solid Medulla?

Answer 20

Pigmented areas filling both the medulla and cortex

Question 21

what is none Medulla?

Answer 21

No separation pigmentation in the medulla

Question 22

Why do crime scene investigators try to collect at least 50 hairs from a crime scene?

Answer 22

To compensate for inconsistencies

Question 23

What are the six types of hair found on the human body?

Answer 23

Head hair, Eyebrow and eyelash, Beard and Mustache Hair, Underarm Hair, Body Hair, and Pubic Hair.

Question 24

What are the three stages of the hair life cycle?

Answer 24

Anagen, Catagen, Telogen

Question 25

Describe the anagen stage.

Answer 25

last roughly 1000 days period of active growth when the cells around the follicle are dividing and depositing material within the hair.

Question 26

Describe the catagen stage.

Answer 26

the hair stops growing, and the follicle recedes

Question 27

Describe the telogen stage.

Answer 27

the hair follicle is dormant and hair is easily lost

Question 28

How does bleaching affect hair?

Answer 28

Oxidizethe natural pigment. peroxide damages mtDNA.

Question 29

What is the difference between artificial and natural bleaching of hair?

Answer 29

Artificial shows sharp demarcations along the hair. Natural leaves a more gradual mark.

Question 30

How much is grown after a month?

Answer 30

1.3 cm

Question 31

How can we estimate when someone last dyed his or her hair?

Answer 31

Measuring the length of hair and then divide by 1.3 provides an estimation.

Question 32

What are the three hair ancestries discussed in class?

Answer 32

European, Asian, and African

Question 33

Describe how Asian hair is different from the other two?

Answer 33

(appearance) straight (pigment granules) Densely distributed (Cross section) round with large diameter (other) Shaft tends to be coarse and straight; thick cuticle; Continuous Medulla; color Black

Question 34

Describe how European hair is different from the other two?

Answer 34

(appearance) straight/Wavy (pigment granules) Small and evenly distributed (Cross section) oval/round of moderate diameter with minimal variation (other) color may be blonde, red, brown, or black

Question 35

Describe how African hair is different from the other two?

Answer 35

(appearance) Kinky, Curly, or Coiled; Shaft may be buckled (pigment granules) Densely distributed clumped, may differ in size and shape (Cross section) flattened with moderate to small diameter and consideration variation.

Question 36

What is the difference in pigmentation in human hair and animal hair?

Answer 36

Human Hair is denser towards the cuticle, Animal Hair is denser towards the medulla.

Question 37

What is the difference in the medullary index for human hair and animal hair?

Answer 37

The ratio of the diameter of the medulla to the diameter of the entire head. o.5 or greater...hair comes from Animal 0.33 or less.. hair comes from Human