forensics 3 and 4
Which of the following characteristics is found in typical Asian hair?
Flattened cross section
Describe the structure of the hair
Had is growing from the follicle and has an inner medulla surrounded by a correct and then the cuticle
Fibers collected as trace evidence are often considered to be class evidence and not individual evidence. For example, the presence of a white cotton fiber found on a suspect and found on a victim at a crime scene is not enough evidence to convict the suspect. Justify this statement.
In many cases, a fiber can be identified, but not connected to a specific person, rather just a certain group of fibers
Explain how the inhalation of asbestos fibers can lead to lung cancer
Inhalation of asbestos fibers can lead to lung cancer because the fibers lodge in the tissue of the lung where their presences causes cells to mutate in a specific way leading to the formation of a cancerous tumor growth.
Why is hair considered class evidence?
It cannot be traced back to a single person unless you don't have the root which has the DNA
Silk is a natural fiber produced by the silk worm. How is silk produced by the body of the silkworm?
They produce the fiber in their bodies and form it from a single strand that measures 1 to 2km.
The cuticle scales of the hair always point towards the...
Tip of the hair
The cortex may contain pigment granules
True
Which factors are used to calculate the medullary index of the hair?
Width of medulla and width of hair
All hairs on a person's head is identical
false
Hair is composed of cellulose
false; keratin
The shiny nature of silk can be related to
its ability to refract light
Natural Fibers can be harvested from
plants, animals, and minerals
mineral fibers such as asbestos are very durable. These fibers are used in all of the following except
rope
neutron activation analysis can check hair for the presence of
silver
what characteristics of cotton make it a great source of fiber for clothing
the fibers are easily woven and dyed
Although variations can occur, which best describes Northern European hair?
Straight with Evenly distributed granules
The body of a woman was found in the woods. Some hair fibers found on the body were sent to the crime lab for analysis. The ends of the hair attached to the body were gray, but the tips of the hair showed that it had been dyed. The distance from the root of the hair to the beginning of the dyed area measured 8 mm. Investigators determined that the victim's hair had last been dyed on August 1, 2004. Assuming the hair grows at the rate of 0.44 mm per day, on approximately what date did the woman die? Explain your answer.
8\44=18.1days
Which of the following is most likely a result of hair bleaching?
A yellowish tint to the hair
What are two ways animal hair differs from human?
Medullary index and cuticle pattern
Human hair has which types of cuticle
Pigmented
Explain why roofers removing old asbestos roofs are more at danger of developing lung cancer than a person who installs asbestos flooring.
Roofers removing old asbestos roofs are more at danger of developing lung cancer than a person who installs asbestos flooring because there is a higher quantity of asbestos in roofs than in floors.
The period of active hair growth is called the _____ stage.
anagen
a characteristic of natural fibers is that they
are affected by microscopic organisms
The hair shaft is composed of the
cuticle, cortex, and medulla
a fiber is collected at a crime. When viewed under a compound microscope,what two traits would indicate that the fiber was a human hair and not a piece of fiber obtained from an article of clothing
the presence of a cuticle an dthe medullary index of 0.33 or less
fibers are an excellent source of trace evidence
they are easily transferred from victim to suspect, easily overlooked by a suspect, easily collected and stored
all of the following are characteristics of a synthetic fiber except:
they do not contain any natural fiber
The shaft of the hair is considered class evidence in a trial
true