Chapter 12: Hairs and Fibers- Test Review

Which of the following is NOT a layer of the hair shaft?

follicle

Which part of the hair shaft is most resistant to chemical decomposition?

cuticle

Which feature of hair is MOST important in making a species identification?

scale pattern

Pigment granules that impart hair with color are found in the

cortex

The central canal running through many hairs is known as the

medulla

Which race is most likely to have head hair with continuous medulla

Mongoloid

A hair sample was examined and its medulla appeared to have a pattern described as resembling a string of pearls. It was most likely from a

cat

In what stage can a hair most readily be removed from the scalp?

telogenic

A human hair in cross-section appeared flat in shape. The racial origin was most likely

Negroid

In determining whether a hair sample originated from a male or female, the MOST important consideration

the results of DNA analysis performed on the root structure

Nuclear DNA typing can be most successfully accomplished on hairs that have been removed during which stage of growth?

anagenic

Which type of crime is LEAST likely to be solved with the use of fiber evidence?

bombing

Mohair and cashmere are hairs from

a goat

By far, the most prevalent plant fiber is

cotton

A fiber microscopic appearance includes being ribbon-like in shape (flat) with twists at irregular intervals is

cotton

Which was the first man-made fiber?

rayon

Which is NOT a synthetic fiber

rayon

The visible light micro-spectrophotometer is a convenient tool with which to compare the color of fibers because

fibers can be studied right on microscope slide; very small samples can be compared; fibers are not destroyed (all of the above)

What type(s) of evidence may result from hit-and-run accidents?

glass

Before the 20th century, all fibers were

natural

A regenerated fiber can be derived from

cotton or wood pulp

Cellulose is the basic component of

wood

The stages of hair growth include all of the following EXCEPT

analgesic

Which of the following is NOT a likely source of human hair?

elbow

This is a transition phase between the other two phases of hair growth, and hair at rest

catagen phase

This can be used to collect hair as evidence

nail polish

These are fibers derived from either natural or synthetic polymers

manufactured fibers

This is the DNA that is present in the nucleus of a cell and that is from both parents

nuclear DNA

This is the main body of the hair shaft, it contains pigments and cortical fusi, gives hair its shape

cortex

This synthetic petroleum fiber that is most durable man made fabric, extremely light weight

nylon

At what location are hair oil produced

sebaceous gland

Fibers are most commonly which type of evidence

class evidence

Which kind of DNA can be extracted from cut hair

mitochondrial DNA

What structure helps your hair rise up when you are cold or nervous

arrestor pili muscle

The cuticle determines the hair color

False

Mitochondrial DNA is present in small structures outside the nucleus of a cell

True

95% of fibers will be lost from a victim for crime scene in the first 42 hours

False

Natural fibers derive from either natural or synthetic polymers

False

A searchable database on CD-ROM of the 45 most common animal hairs encounter in forensic casework is commercially available

False

Cotton is a type of synthetic fiber

False

Nylon is a natural fiber

False

When collecting fiber evidence from different locations, it should be placed in separate containers

True

Infrared spectrophotometry and the polarizing microscope are reliable methods for identifying the chemical composition

True

Follicular tag contains the richest source of DNA associated with hair

True

6 different types of synthetic fibers

nylon, polyester, acetate, spandex, acrylic, rayon

5 different types of natural fibers

cotton, silk, wool, mohair, cashmere

2 different animal fibers that are mostly made of protein

silk and wool

3 mineral fibers that are studied in forensics

absetos, fiberglass, metallis (mylor)

4 synthetic fibers made from derivatives of petroleum, coal and natural gas

nylon, polyester, argyle, spandex

What are three growth phases of a hair follicle

anagen phase, catagen phase, telogen phase

4 different types of a weave

plain, twill, satin, knit

2 different plant fibers

cotton and ramie

Why must questioned hairs and standard/reference hairs being compared come from the same area of the body

Because hairs differ on different parts of the body