1.1.3 The Traces We Leave Behind

What is the only type of hair you can get DNA from?

The root

What is hair made up of?

Dead cells surrounded by Keratin

The cuticle

-outermost layer of the hair

-the layer most likely to show damage

-consists of flattened, scale-like cells which overlap one another (non repeating pattern)

The cortex

-the intermediate layer

-home to the pigment-containing granules responsible for hair color

-contains many of the characteristics used in the microscopic analysis of hair

-organization, density, size, and distribution of the pigment granules

The medulla

-innermost layer of hair

-Types

• Continuous

• Discontinuous (broken but evenly spaced)

• Fragmentary (unevenly spaced)

• Absent