Hair
Is hair class or individual?
Hair is class evidence unless it contains the follicular tag, then it is individual
Are fibers class or individual?
It is class unless there is a specific situation where DNA is found on it
Is glass class or individual?
It is most commonly class unless it can be put together and traced to a single origin
Is soil class or individual?
Soil can be both depending on what it contains. If it can be traced back to a single location based on the pollen or other contents, then it is individual.
The central core of the hair is called?
medulla
Natural and synthetic
Which fractures are primary vs secondary?
Radial fractures are primary and concentric are secondary
Three main types of soil textures:
Slit, clay, sand
How do you know if a hair has been forcefully wripped out?
if the root is bent or elongated
Three characteristics of fibers:
color, texture, pH
Which side do concentric vs radial lines form?
concentric: same, radial: opposite
Put the types of soil in order based on size from smallest to largest:
clay, slit, sand
keratin
Provide three examples of synthetic vs natural fibers
rayon, nylon, acrylic vs cotton, silk, wool
What is the difference between laminated and tempered glass?
Laminated cracks in layers, and tempered glass shatters
What has to be made sure of before testing soil?
It has to be dry because the color will be darker if its wet
What is the medullary index of animals vs. humans?
over .5 vs under .33
Two methods for analyzing fibers are:
polarizing light microscopy and infrared spectroscopy
What is a Becke line?
A Becke line appears when the glass and liquid have a different refractive index
What is the humus?
the organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms