Describe the process of comparing two fibers via microscopic and ...

[armygirl]

Describe the process of comparing two fibers via microscopic and analytical methods. What morphological characteristics should a criminalist compare in these steps?
 
  What will be an ideal response?

Question 2

During a microscopic comparison of two hairs, a trace analyst compares the medullae of the hairs to determine species of origin.
 
  What is the difference between the medullae of human and animal hairs? Name one exception to this among humans that may help in these determinations.
  What will be an ideal response?

[Pariscourtney]

Answer to Question 1

Answer should include points such as the following:
A criminalist first microscopically compares the color and diameter of the fibers. Other morphological features that may aid in the comparison are lengthwise striations (i.e., lined markings) on the surface of some fibers and the pitting of the fiber's surface with delustering particles added in the manufacturing process to reduce shine. The cross-sectional shape of a fiber may also help characterize the fiber. Confirmation of a color comparison can then be made by comparing the fibers' spectral patterns with a microspectrophotome ter. A physical characteristic that frequently is used to identify fibers is the infrared absorption spectrum.

Answer to Question 2

Answer should include points such as the following:
Most animals have medullae that are either continuous or interrupted. Human head hairs generally exhibit no medullae or have fragmented ones; they rarely show continuous medullation.
One exception is in the Mongoloid race, whose members usually have head hairs with continuous medullae.