Forensics Exam 1

Human hair grows at an approximate rate of ____cm per month

1.3

______ was the first comparison microscope use (date)

1934

Hair analysis has been used since the ____ century

19th

Toxins found at 9 cm contains materials ingested ___________ ago.

7 months

True or false All hairs on the head of a person are identical

False

Securing the crime scene is the duty of the

First responder

____________principle: when a person comes into contact with an object or another person, a cross transfer of physical evidence can occur

Locard's exchange

What are the 7 "s" of CSI

Securing the crime scene, Separate witnesses, Scan the crime scene, see the crime scene, sketch the crime scene, search for evidence, secure evidence

_______________________________- 1910 study of microscopic images of human and animal hair (first known reference guide)

The hair of man and animals

True or False The shaft of the hair is considered class evidence in a trial

True

True or false Hair can provide clues about someone's ancestry

True

A characteristic of natural fibers is that they a. are affected by microscopic organisms b. will break down when exposed to bright light c. melt at a lower temperature than synthetic fibers d. are stronger than synthetic fibers

a

All of the following should appear on an evidence label except a. postmorten interval b. date, time c. name of collector d. case number

a

Human hair has which type of cuticle a. imbricate b. spinous c. coronal d. pigmented

a

Mineral fibers such as asbestos are very durable. These fibers have been used in all of the following except a. rope b. shingles c. floortiles d. brake linings

a

The type of weave pattern of a fabric affects all of the following except a. shiny appearance b. stretch of a fabric c. solubility in water d. strength of fabric

a

Which of the following is most likely a result of hair bleaching a. increased number of disulfide bonds b. oxidized hair and damaged DNA c. a more triangular cross section d. thickened scales on the cuticle

a

Class evidence narrows the evidence to:

a group of people

Individual evidence narrows the evidence to:

an individual

______________- group of plants in an area dominated by one species that share the same habitat requirements

assemblage

Although variations can occur, which of the following best describes European hair? a. kinky with dense, unevenly distributed pigment b. straight or wavy with evenly distributed granules c. round cross section with a large diameter d. coarse with a thick cuticle and a continuous medulla

b

Locard's Principle of exchange implies all of the following except a. Fibers can be transferred from one person to another b. Blood spatter can be used to identify blood type c. Cat hair can be transferred to your pants d. Soil samples can be carried from the yard into your home

b

Microscopic hair analysis a. yields individual evidence b. is used to exclude a suspect c. can prove a suspect's guilt d. can determine maternal inheritance

b

The period when hair is naturally shed is called the _____________ stage. a. catagen b. telogen c. anagen d.imagen

b

The shiny nature of silk can be related to a. its hollow core b. its ability to reflect light c. its smooth, round fibers d. mucus secretions from the silkworm

b

Which of the following characteristics is found in typical Asian hair? a. dark medulla b. sparsely distributed pigment granules c. flattened cross section d. curls

b

Diatoms a. are visible to the naked eye b. have a cell wall composed of rigid cellulose c. are found attached to rocks and plants in bodies of water d. are used to assist in crime scenes involving insects

c

The reason it is important to separate the witnesses at the crime scene is it a. prevent contamination of the evidence b. prevent fighting among the witnesses c. prevent the witnesses from talking to each other d. protect them from the perpetrator

c

What characteristics of cotton make it a great source of fiber for clothing a. its a polymer of keratin b. it is resistant to staining c. The fibers are easily woven and dyed d. The fibers are extremely long

c

Which factors are used to calculate the medullary index of the hair a. scale diameter of cuticle and the length of the hair b. width of cortex and the width of the medulla c. length of entire hair and the pattern of pigmentation d. width of medulla and the width of the hair

c

Plant fibers all share the same polymer: ____________

cellulose

Hair is considered _______ evidence.

class

Two Types of Circumstantial evidence:

class and Individual

In humans the _______ is the largest part of the hair shaft

cortex

_____________- region of the hair located outside the medulla that contains granules of pigment

cortex

seed fibers are typically used in:

cotton

________-tough outer covering of a hair that is composed of overlapping scales

cuticles

A crime-scene sketch should include all of the following except a. a distance scale b. date and location of the crime scene c. a north heading d. the type of search pattern used to collect the evidence

d

Animal hair can be distinguished from human hair because animal hair a. has a smaller medullary index than human hair and no cortex b. does not have a cuticle c. always has a continuous medulla pattern d. has a greater medullary index and more variation in the cuticle patterns

d

Botanical evidence is a valuable source of evidence because a. it is easily overlooked by perpetrators b. many plants have adaptations that make them easily transferred c. the collection of plants in an area can help identify an area d. all the above

d

Correct collection of evidence requires which of the following? a. documenting the location where the evidence was found b. correct packaging of evidence c. maintaining proper chain of custody d. all of the above

d

Hair can be used to determine a. diet b. drug habits c. geographic history d. all of the above

d

Natural fibers can be harvested from a. plants and animals b. only from plants c. only from animals d. plants. animals, and minerals

d

Which part(s) of a hair can be analyzed for nuclear DNA? a. follicle b. shaft c. medulla d. all of the above

d

Two types of evidence:

direct, circumstantial

True or False Hair is composed mostly of a protein called cellulose

false

Direct evidence is:

first hand accounts (weapon, video)

A datum point is a

fixed object (like a post or cement pillar)

____________-the actively growing base of a hair that contains DNA and living cells

hair follicle

________________-part of the hair above the follicle; contains mitochondrial DNA

hair shaft

What are three examples of evidence:

hair, fingerprints, fiber

stem fibers are typically used in

hemp

Circumstantial evidence is:

indirect evidence that can be used to imply, but not prove

What three things depend on the extent of the transfer of evidence?

intensity, duration, nature

What is triangulation?

mathmatical method to calculate the location of an object from the location of other objects

____________-the central core of the hair

medulla

______________- the ratio of the medulla to the diameter of the entire hair

medullary index

The cortex contains the most _________________.

melanin granules

___________-genetic material in the mitochondria of the cytoplasm of a cell (only inherited from mother)

mitochondrial DNA

polymers are long repeating _____________

molecules

Synthetic fibers are made from:

monomers

After securing evidence, what are the four things that need to happen to the evidence:

package, seal, catalog, chain of custody

________________-the study of pollen and spores

palynology

5 ways to differentiate between hairs

pigment, chemical, medullary index, medulla type, ethnicity

_________- the number and type of pollen grains found in a geographic area at a particular time of year

pollen fingerprint

Fibers are composed of ____________

polymers

____________-time elapsed between a person's death and discovery of the body

post-mortem interval

What are two reasons to separate witness's

prevent collusion, prevents contamination of direct evidence

Three things to look for when finding grave sites:

settling, new assemblage, unique plants

Five different types of medulla

solid, none, hollow, absent, fragmented

What are 3 technologies used when searching the crime scene for evidence?

sonar, black lights, radar

What are two purposes to sketching a crime scene

to note position of remains and where other evidence is

What is the 3 reasons to secure a crime scene

to protect it, prevent intrusions, prevent contamination

A greater number of fibers found on the victim could indicate a greater level of:

violence

Multiple locations of fibers on a victim could suggest two things:

violence, prolonged contact

What 4 things can you find while doing chemical testing on hair?

water, food, toxins, drugs

4 objects that are used to collect fiber evidence

tape, forceps, vacuum, lint roller