Deck 16: DNA: The Indispensable Forensic Science Tool

Question 1

The technology of DNA typing had its beginnings in 1985 with the work of:

A)Henry Lee.
B)Francis Crick.
C)James Watson.
D)Alec Jeffreys.

Answer 1

D

Question 2

The separation of STRs using capillary electrophoresis:

A)Evolved from the flat-gel electrophoresis approach.
B)Decreases analysis time.
C)Is currently the preferred method.
D)All of the above

Answer 2

D

Question 3

The discriminating power of mtDNA is ________ the discriminating power of STR analysis.

A)Greater than
B)The same as
C)Less than
D)None of the above

Answer 3

C

Question 4

Which of the following depicts correct base-pairing in DNA?

A)A-U
B)G-A
C)T-A
D)C-T

Question 5

PCR is a technique that:

A)Provides a statistical analysis of the nitrogenous-base pairings.
B)Can produce many exact copies of segments of DNA.
C)Produces information regarding the sequence of nitrogenous bases.
D)Virtually eliminates operator error from DNA analysis.

Question 6

Which component of DNA forms the backbone of the molecule?

A)Phosphate group
B)Nitrogenous base
C)Sugar
D)Both A and C

Question 7

STR analysis has replaced other DNA typing techniques because it:

A)Is less subject to sample degradation.
B)Requires a smaller sample size.
C)Can be implemented using the PCR.
D)All of the above

Question 8

What is an advantage of working with short DNA fragments?

A)They are more stable and less likely to break apart.
B)Their quantity can be greatly amplified by PCR technology.
C)They are less subject to degradation due to adverse environmental conditions.
D)All of the above

Question 9

Which is NOT a component of a nucleotide?

A)Phosphorous-containing group
B)Double helix
C)Sugar
D)Nitrogenous base

Question 10

In DNA replication, polymerases:

A)Enable the strands to unwind from the helix.
B)Help assemble the new DNA strands in proper base sequence.
C)Separate the strands of the double helix.
D)All of the above

Question 11

The molecular structure of DNA was deduced by:

A)Gregor Mendel.
B)Francis Crick.
C)James Watson.
D)Both B and C

Question 12

Which nitrogenous base is NOT found in DNA?

A)Thymine
B)Cytosine
C)Uracil
D)Adenine

Question 13

CODIS is a national system of:

A)Computers to track the movement of sex offenders released from prison.
B)Shared databases of DNA typing information from convicted felons and crime-scene evidence.
C)Vastly enhanced 911 emergency systems.
D)Crime laboratory directors.

Question 14

DNA is a(n):

A)Protein.
B)Starch.
C)Polymer.
D)Enzyme.

Question 15

Which statement is NOT true? Few forensic labs do analysis of mtDNA because:

A)Little mtDNA is present in a cell.
B)The analysis procedure is very rigorous.
C)It costs much more than nuclear DNA profiling.
D)Such study takes a long time.

Question 16

The building blocks of the DNA molecule are known as:

A)Amino acids.
B)Nucleotides.
C)Polysaccharides.
D)Hydrocarbons.

Question 17

Amplifying DNA using the Thermal Cycler takes approximately:

A)30 cycles.
B)4 cycles.
C)2 hours.
D)2 minutes.

Question 18

In the PCR process, the first step is to heat the DNA strands. This is to permit the:

A)DNA to coil very tightly in the helical shape.
B)Process to take place without DNA degradation.
C)Hybridization to take place.
D)Double-stranded molecules to separate completely.

Question 19

The PCR technique requires the use of a thermal cycler to:

A)Synthesize protein.
B)Copy DNA.
C)Make probes radioactive.
D)Hydrolyze polymerase.

Question 20

Means to detect the amelogenin gene are included in commercial STR kits used in crime labs because the gene allows determination of:

A)Ethnicity.
B)Blood type.
C)Gender.
D)Eye color.

Question 21

The specific proteins produced by a cell are directly related to the:

A)Sequence of nucleotides in the DNA of the cell.
B)Number of mitochondria in the cell.
C)Length of the chromosomes.
D)Sequence of sugars and phosphates in the cell.

Question 22

In which hereditary disease does abnormal hemoglobin differ from normal hemoglobin by only a single amino acid?

A)Phenylketonuria
B)Hemophilia
C)Sickle-cell anemia
D)Albinism

Question 23

Which statement about mitochondrial DNA is INCORRECT?

A)Mitochondrial DNA is located outside the cell's nucleus.
B)Mitochondrial DNA is constructed in a loop configuration.
C)Many copies of mitochondrial DNA's hypervariable regions are made by PCR.
D)The number of repeat segments found in the hypervariable regions are used to type mitochondrial DNA.

Question 24

The rate at which large DNA fragments move through the electrophoretic gel is ________ the rate at which small DNA fragments move through the same apparatus.

A)The same as
B)Greater than
C)Less than
D)None of the above

Question 25

The individuality of an organism is determined by the organism's:

A)DNA nucleotide sequence.
B)Nitrogenous bases.
C)Amino acids.
D)Environment.

Question 26

What is the number of nitrogenous bases needed to code for a specific amino acid?

A)2
B)3
C)5
D)6

Question 27

Portions of the DNA molecule useful for DNA typing:

A)Code for the production of proteins.
B)Are useful for recombinant DNA.
C)Are repeated many times.
D)Are useful for the production of insulin.

Question 28

Information from the Human Genome Project will:

A)Help reveal the role and implications of evolution.
B)Be useful for diagnosing and treating genetic diseases.
C)Reveal the location of a gene on a particular chromosome.
D)All of the above

Question 29

What are examples of polymers that contain repeating units known as nucleotides?

A)Hemoglobin
B)Starch
C)Cellulose
D)DNA

Question 30

HV1 and HV2 are:

A)Restriction enzymes.
B)STR types.
C)Types of viruses.
D)Regions of mtDNA.

Question 31

Use this DNA STR pattern of evidence from a rape investigation to answer the following question(s).

The evidence suggests which suspect raped the victim?

A)Suspect A
B)Suspect B
C)Suspect C
D)The evidence shows that none of these suspects is a match.

Question 32

The production of amino acid is coded by a sequence of how many bases on the DNA molecule?

A)2
B)3
C)4
D)5

Question 33

Assume that two strands of DNA have been separated and that the base sequence on one strand is ATGC. What is the sequence of bases on the second strand?

A)GCAT
B)ACTC
C)TGGC
D)TACG

Question 34

Which statement is INCORRECT regarding Y-STRs?

A)Female STRs will not yield a Y-STR profile.
B)Y-STRs can be amplified by PCR.
C)Y-STR types are typically shorter in length as compared to X-STRs.
D)A typical Y-STR pattern has one band.

Question 35

Which statement regarding STRs is true?

A)Restriction enzymes are used to cut STRs from the DNA helix.
B)There is little variation in the number of repeats from person to person.
C)All humans have the same type of STRs.
D)Typically a core repeat sequence would consist of 15-30 bases.

Question 36

Which statement about tandem repeats is NOT true?

A)More than 30% of the human genome is composed of these repeating units.
B)Their origin is a mystery.
C)It is thought that they may act as spacers between the coded regions of DNA.
D)They are of no forensic interest.

Question 37

How many different bases are associated with the makeup of DNA?

A)3
B)4
C)5
D)6

Question 38

Y-STR markers are useful when multiple males are involved in a sexual assault. If three men are involved in such an attack the investigators would expect Y-STR analysis to show a maximum of:

A)Eight peaks.
B)Three peaks.
C)Six peaks.
D)Four peaks.

Question 39

The concept of simultaneously extracting, amplifying, and detecting a combination of STRs is known as:

A)PCR.
B)THO1.
C)Multiplexing.
D)Electrophoresis.

Question 40

Note that suspect B has only one band in his lane. This is most likely an indication that:

A)He is homozygous for the gene.
B)He is trisomic for the trait.
C)His DNA was contaminated during the collection process.
D)He is heterozygous for the gene.

Question 41

The four bases on the DNA molecule are paired with A opposite T and G opposite C.

Question 42

DNA analysts are able to examine samples containing as few as ________ cells for an STR profile.

A)18
B)36
C)180
D)800

Question 43

Small amounts of blood are best submitted to a crime laboratory:

A)Immediately while still wet.
B)In a druggists fold.
C)After dried.
D)After removal from surface of deposition and rehydration.

Question 44

PCR are regions of a chromosome that contain multiple copies of a core DNA sequence arranged in a repeating fashion.

Question 45

How should blood-containing clothes from a victim be packaged?

A)In an airtight metal container
B)In an airtight clear plastic container
C)In a metal paint can
D)In breathable paper after blood has dried

Question 46

Longer DNA strands are more stable and less subject to degradation than shorter strands.

Question 47

The amount of DNA material required for STR analysis is ________ the amount of DNA required for RFLP analysis.

A)The same as
B)Greater than
C)Less than
D)None of the above

Question 48

Mitochondrial DNA analysis is significantly more sensitive than nuclear DNA profiling.

Question 49

The greater the number of STRs characterized, the smaller the frequency of occurrence of the analyzed sample in the general population.

Question 50

A short tandem repeat (STR)is a region of a DNA molecule that contains short segments consisting of 50-100 repeating base pairs.

Question 51

A conventional STR profile emanating from a mixture of DNA from male donors yields four peaks or bands for each locus present. How many peaks or bands would you normally expect for each locus if a Y-STR profile is performed on the same sample?

A)One
B)Two
C)Three
D)Four

Question 52

Mitochondrial DNA is found in the nucleus of each cell and is inherited from both parents.

Question 53

Proteins are formed by linking a combination of nucleotides.

Question 54

A typical STR DNA type emanating from a single individual shows a ________-band pattern.

A)1
B)2
C)3
D)0

Question 55

STRs normally consist of repeating sequences of:

A)13-17 bases.
B)18-2 bases.
C)3-7 bases.
D)8-12 bases.

Question 56

Electrophoresis can be used in the crime lab to analyze:

A)DNA.
B)Proteins.
C)dried blood.
D)All of the above

Question 57

________ region(s)of mitochondrial DNA have been found to be highly variable in the human population for forensic determinations.

A)1
B)2
C)3
D)4

Question 58

Each cycle of the DNA Thermal Cycler takes approximately:

A)30 seconds.
B)4 hours.
C)2 hours.
D)2 minutes.

Question 59

Tandem repeats are useful for forensic scientists because they provide a way to distinguish one individual from another through DNA typing.

Question 60

James Watson and Francis Crick are credited with discovering the structure of DNA.

Question 61

Capillary electrophoresis is the preferred technology for characterization of STRs.

Question 62

The more STRs a forensic scientist can characterize, the greater is the likelihood that they originated from two different individuals.

Question 63

________ is a technique for replicating or copying a portion of a DNA strand outside a living cell.

Question 64

The synthesis of new DNA from existing DNA is known as hybridization.

Question 65

STR analysis is the most successful and widely used DNA profiling procedure.

Question 66

________ is a technique that simultaneously detects more than one STR in a single DNA analysis.

Question 67

________ are male-specific and are useful for characterizing multiple-male DNA mixtures.

Question 68

The X-STR gene can reveal the sex of the person who contributed a DNA sample.

Question 69

DNA is a large molecule called a polymer, created by linking a series of repeating units known as ________.

Question 70

Electrophoresis is widely used in the characterization of proteins and DNA in dried blood.

Question 71

Mitochondrial DNA is arranged in a circular loop of bases, while nuclear DNA is arranged in a continuous strand of bases.

Question 72

The four bases associated with DNA are adenine, cytosine, guanine, and ________.

Question 73

Collected swabs must NOT be packaged in a wet state.

Question 74

________ is the molecule that carries the body's genetic information.

Question 75

Buccal cells are derived from the inner cheek lining.

Question 76

Decoding the human ________ can be useful for diagnosing and treating genetic diseases.

Question 77

A ________ is a threadlike structure in the cell nucleus along which the genes are located.

Question 78

The ________ gene is often used to determine the sex of a DNA contributor.

Question 79

Blood in soil must be stored in a clean glass or plastic container and immediately frozen.

Question 80

________ repeats are regions of a chromosome that contain multiple copies of a core DNA sequence arranged in a repeating fashion.