Forensic Hair and Fiber Analysis Quiz

Why is hair considered both class and individual evidence?

• If nuclear DNA can be retrieved from a hair sample, then the hair can provide the specific identity of the individual.

• If nuclear DNA cannot be retrieved, then the hair can provide class evidence by the appearance of the hair or its mtDNA and provide about the maternal line of the individual.

• Hair cannot provide any evidence.

• Hair only provides class evidence.

Tags

NGSS.HS-LS3-2

Why are hairs and fibers considered trace evidence?

• Due to its small size, a criminal can unknowingly leave hair or fiber behind at a crime scene, providing evidence for forensic investigators.

• They are too large to be considered trace evidence.

• They are not used in forensic investigations.

• They are always visible to the naked eye.

What is the difference between nuclear DNA and mtDNA (mitochondrial DNA)?

• Nuclear DNA (found within the cell's nucleus) provide individual evidence.

• Mitochondrial DNA (mtDNA) (no follicle is retrieved) can be used to reveal family relationships.

• Nuclear DNA is found in the mitochondria.

• mtDNA provides individual evidence.

Describe the three stages of hair growth.

• Anagen stage: hair is growing.

• Catagen stage: blood supply to the follicle is reduced, and the hair is no longer growing.

• Telogen stage: hair is easily lost.

• All of the above.

Describe the two main structures of hair.

• Hair follicle: the actively growing base of a hair that contains DNA and living cells.

• Hair shaft: part of the hair above the follicle; contains mitochondrial DNA.

• Hair root: the part of the hair that is visible.

• Hair tip: the end of the hair.

Tags

NGSS.MS-LS1-5

Describe the three structures that make up the hair shaft.

• The cuticle is a transparent outer layer of the hair shaft that protects the inner layers of the hair.

• The cortex is the part of the hair that contains most of the melanin granules that give the hair its color.

• The center of the hair is called the medulla.

• All of the above.

What are the three main differences between human hair and nonhuman hair?

• Pattern of pigmentation, medullary index, cuticle type

• Color, length, texture

• Thickness, strength, elasticity

• Growth rate, density, shine

What is the medullary index?

• The ratio of the diameter of the medulla to the diameter of the entire hair is known as the medullary index.

• The length of the hair divided by its width.

• The thickness of the hair shaft.

• The color intensity of the hair.

What type of cuticle do humans have?

• Imbricate

• Coronal

• Spinous

• None

How does bleaching/dyeing affect the hair?

• It changes the appearance of the cuticle and cortex. It also can damage and destroy the mtDNA found in the hair shaft.

• It makes the hair grow faster.

• It strengthens the hair.

• It has no effect on the hair.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5