Forensics Chapter 3
The use of the comparison microscope to perform side-by-side analysis of hair collected from the crime scene and hair from a suspect or victim first occurred in:
1934
When humans are born, they have about:
5 million hair follicles, only two percent of which are on the head.
Whenever two objects are in contact, some transfer of material will occur. This is known as
Locard's exchange principle
Since hair grows out of the skin, chemicals that the skin absorbs can become incorporated into hair. Ingested or absorbed toxins can be detected by chemical analyses of hair. These ingested or absorbed toxins include:
arsenic. lead. drugs.
Hair is considered:
class evidence.
The cuticle is a transparent inner layer of the hair shaft.
false
The hair shaft is made up of three layers: an outer medulla, a cortex, and an inner cuticle.
false
Many dyes and other hair treatments will fluoresce under a certain color (wavelength) of light. In a fluorescence microscope, a beam of light of a certain color is used. If the sample contains particular chemicals, it will absorb some of the light and then reemit light of a different color. This is called:
fluorescence.
If hair is forcibly removed from a victim, the entire hair follicle may be present. This is called a:
follicular tag
A classic 1883 text on forensic science, The Principles and Practice of Medical Jurisprudence by Alfred Swaine Taylor and Thomas Stevenson, contains a chapter on using:
hair in forensic investigations
The cuticle of human hair is described as
imbricate
A type of fibrous protein that makes up the majority of the cortex of a hair is:
keratin
The central core of a hair fiber is called the
medulla
In 1910 a comprehensive study of hair titled The Hair of Man and Animals was published by the French forensic scientists, Victor Balthazard and Marcelle Lambert. This text includes numerous microscopic studies of hair from:
most animals.
Animal hair and human hair have several differences, including:
pattern of pigmentation medullary index cuticle type
Hair viewed for forensic investigations is studied both macroscopically and microscopically. Microscopic characteristics include the:
pattern of the medulla pigmentation of the cortex types of scales
All mammals have hair. Its main purpose is to
regulate body temperature--to keep the body warm by insulating it.
Hair can adhere to clothes, carpets and many other surfaces and be transferred to other locations. This is called:
secondary transfer.
Forensic scientists distinguish ( ) types of hair on the human body.
six
The region of a hair located outside of the medulla containing granules of pigment is called:
the cortex
Hair proceeds through ( ) stages as it develops.
three
Investigators recognized the importance of analysis of hair as:
trace evidence in criminal investigations in the late 1800s.
A hair consists of two parts: a follicle and a shaft
true
Bits of pigment found in the cortex of a hair is called melanin granules.
true
In humans, the cortex is the largest part of the hair shaft.
true
