Science Olympiad - Crime Busters Fibers & Hairs

Human hair

What type of hair is this?

Cat hair

What type of hair is this?

Dog hair

What type of hair is this?

Medulla, Cortex, Cuticle

What are the three layers of hair?

Medulla

What layer of hair is this (C)?

Cortex

What layer of hair is this (B)?

Cuticle

What layer of hair is this (A)?

The cortex

What layer of hair contains your hair pigment?

Melanin

(Eumelanin and Pheomelanin)

What is hair pigment called?

Considered class evidence; if the root is intact and DNA can be collected then it is individual evidence.

What kind of evidence is hair considered to be?

Medullary index for human hair is generally less than 1/3.

What is the medullary index for human hair?

For animal hair, it is usually greater than 1/2.

What is the medullary index for animal hair?

Anagen

What is the first phase of the hair cycle?

Catagen

What is the second phase of the hair cycle?

Telogen

What is the third phase of the hair cycle?

Exogen

What is the final phase of the hair cycle?

Active growth; producing new cells

What happens in the anagen phase?

Stops growing; slowly detaching

What happens in the catagen phase?

Follicle rest; prepares for new cycle

What happens in the telogen phase?

Shedding phase

What happens in the exogen phase?

Vegetable, synthetic, and animal

What are the three types of fibers?

Cotton and linen

What are the two types of vegetable fibers used in Crime?

Wool and silk

What are the two types of animal fibers used in Crime?

Nylon, polyester, acrylic, and rayon

What are the four types of synthetic fibers used in Crime?

Vegetable (cotton)

What fiber is this?

Vegetable (linen)

What fiber is this?

Animal (Wool)

What fiber is this?

Animal (Silk)

What fiber is this?

Synthetic (Nylon)

What fiber is this?

Synthetic (Polyester)

What fiber is this?

Synthetic (Acrylic)

What fiber is this?

Synthetic (Rayon)

What fiber is this?

Smells like burning hair; small flickering flame, brittle ash, no smoldering; self-extinguishing

Describe a burn test for wool

Smells like burning feathers; calm, no smoldering, black beads, crushable; self-extinguishing

Describe a burn test for silk

Smells like burning paper; flame amber or yellow, slow burning, fluffy, grayish ash; continues to burn

Describe a burn test for cotton

Describe a burn test for linen