Chapter 9—DNA Forensics
MULTIPLE CHOICE
1. ____ are repeated sequences of 10−100 base pairs that are used for developing DNA profiles.
a.
Minisatellites
b.
STRs
c.
RFLPs
d.
SNPs
e.
Mitochondrial DNA
2. Single nucleotide polymorphisms (SNPs)
a.
consist of one nucleotide differences.
b.
are based on the number of repeated sequences present.
c.
are found in minisatellites.
d.
are used to amplify small amounts of DNA.
e.
requires cutting by restriction enzymes.
3. Why are minisatellites important for DNA analysis?
a.
They are useful for determining the sex of the criminal.
b.
Variation in the number of repeats is used in preparing DNA profiles.
c.
They are used when there is no DNA available to analyze.
d.
They can help geneticists determine the inheritance pattern of a trait.
e.
Data from minisatellite analysis is stored in the FBI database.
4. Which of the following statements about STRs is FALSE?
a.
They are only 2−9 bases long.
b.
Clusters are found widely distributed on all human chromosomes.
c.
Variation in the number of repeats is used in preparing DNA profiles.
d.
They consist of differences in DNA sequences that are only one nucleotide long.
e.
They consist of short repeated nucleotide sequences.
5. Which of the following DNA elements have NOT been used to develop DNA profiles?
a.
minisatellites
b.
STRs
c.
RFLPs
d.
telomeres
e.
All of these have been used to develop DNA profiles.
88
6. DNA fragments are separated in an agarose gel based on
a.
size, with the shortest DNA fragments traveling farthest.
b.
size, with the longest DNA fragments traveling the farthest.
c.
the presence or absence of certain SNPs.
d.
the number of strands in the DNA fragments.
e.
the frequency of particular DNA nucleotides.
7. PCR is a valuable tool for DNA forensics. It
a.
allows the generation of instant DNA profiles from large amounts of DNA.
b.
allows the generation of DNA profiles from very small amounts of DNA.
c.
is the only tool used to generate DNA profiles.
d.
allows small amounts of DNA to be visualized under the microscope.
e.
allows large amounts of DNA to be visualized under the microscope.
8. All of the following are required to perform PCR EXCEPT
a.
DNA primers.
b.
DNA polymerase.
c.
specialized machinery.
d.
sample DNA.
e.
restriction enzymes.
9. The amount of target DNA ____ with each PCR cycle.
a.
doubles
b.
triples
c.
increases 10 times
d.
remains constant
e.
is cut in half
10. A DNA sample from an individual is analyzed. The population frequency of one of the STR alleles is
1 in 50, a second STR allele is 1 in 100, and a third STR allele is 1 in 30. What is the combined
frequency of these three STR alleles?
a.
1 in 150,000
b.
1 in 15,000
c.
1 in 1,500
d.
1 in 180
e.
1 in 50
11. The polymerase chain reaction (PCR) uses ____ to amplify a particular stretch of DNA.
a.
DNA polymerase
b.
RNA polymerase
c.
restriction enzymes
d.
ribosomes
e.
repeated sequences
Chapter 9 – DNA Forensics
12. The use of scientific knowledge in civil and criminal law is
a.
forensics.
b.
recombinant DNA technology.
c.
reproductive technology.
d.
the human genome project.
e.
DNA profiling.
13. All of the following are possible sources of DNA for analysis EXCEPT
a.
mummies.
b.
toothbrushes.
c.
licked envelope flaps.
d.
cigarette butts.
e.
mature red blood cells.
14. Analysis of STRs shows that
a.
the more alleles that are analyzed, the more frequent the combinations become in a
population.
b.
the more alleles that are analyzed, the rarer the combinations become in a population.
c.
all STR alleles occur at equal frequency..
d.
the usefulness of STRs for DNA profiling is very limited.
e.
None of these are correct.
15. What was the first U.S. court case to challenge the admissibility DNA evidence?
a.
Frye v. U.S.
b.
People v. Castro
c.
Narborough Village Murders
d.
Jennifer Thompson-Canino v. Ronald Cotton
e.
Margaret Sackler v. William Bern
16. What was the landmark U.S. court case to determine whether scientific evidence should be admissible
as “good science”?
a.
Frye v. U.S.
b.
People v. Castro
c.
Narborough Village Murders
d.
Jennifer Thompson-Canino v. Ronald Cotton
e.
Margaret Sackler v. William Bern
17. Which of the following statements about haplotypes is FALSE?
a.
Haplotype analysis can provide information about ancestry.
b.
Each person has the same mtDNA haplotype as his or her mother.
c.
Y chromosomal haplotypes can be used to trace paternal lineage.
d.
Haplotypes are based on differences in DNA sequence.
e.
Haplotypes analysis is only useful to determine paternity.
18. What is the pattern of inheritance of mitochondrial DNA?
a.
It is passed from a mother to all of her children.
b.
It is passed from a father to all of his sons.
c.
It is passed from a mother only to her sons.
d.
It is passed from a father to all of his daughters.
e.
It is passed from a mother only to her daughters.
19. The Combined DNA Index System (CODIS)
a.
uses a panel of 13 different STRs.
b.
contains information from every American citizen.
c.
contains information from any person suspected of committing a crime.
d.
is only used to determine paternity.
e.
None of that are correct.
20. The two types of testing typically offered to trace one’s ancestry are
a.
mitochondrial DNA and Y-chromosome testing.
b.
Y chromosome and minisatellite DNA testing.
c.
X chromosome and Y-chromosome testing.
d.
minisatellite DNA and X-chromosome testing.
e.
full genomic sequencing.
21. In PCR, primers
a.
are the enzyme which carries on the reaction.
b.
refer to the DNA isolated from the sample in question.
c.
are short nucleotide sequences.
d.
are the individual A, C, G, and T nucleotides.
e.
are the copies produced by the process.
TRUE/FALSE
1. Analysis of mtDNA or Y chromosomes provides data that allows people to trace their ancestry.
91
2. DNA profiles have been developed from the remains of dead people.
3. Two common techniques used in DNA forensics are restriction fragment length polymorphism
analysis and the polymerase chain reaction.
4. DNA profiles can be prepared from very small DNA samples.
5. DNA profile analysis has led to the release of individuals who were wrongly convicted of crimes.
6. DNA evidence has only been admitted for use in courts for murder cases.
7. Kary Mullis, the inventor of PCR, owns the patent for the invention.
8. When an electric current is passed through an agarose gel, the migration of DNA fragments through
the gel is based on the number of copies of each fragment.
9. DNA is unstable and breaks down after a year or so.
10. All STRs are located on the X chromosome.
MATCHING
Match the appropriate term with the description.
a.
useful for tracking maternal ancestry
b.
passed only from fathers to sons
c.
information stored in CODIS
d.
a series of specific DNA markers
e.
repeated sequences of 10-100 base pairs in length
f.
DNA differences that are only one base pair long
g.
method to make many copies of a segment of DNA
h.
analysis using restriction enzymes
92
1. mtDNA
2. Y chromosome
3. haplotypes
4. minisatellites
5. SNP
6. RFLPs
7. STRs
8. PCR
ESSAY
PTS: 1
2. Do you think mandatory DNA profiling should be done for all U.S. military personnel? Why or why
not? Could this mandatory profiling be considered a violation of the individual’s human rights?
Explain your answer.
3. Various recommendations have been made concerning DNA profiling of all persons who have
committed a felony. Would you consider this a violation of the individual’s human rights? Indicate
how this type of information could be useful in locating and identifying criminals implicated in future
assaults and rapes and in the associated court cases?
Chapter 9 – DNA Forensics
SHORT ANSWER
1. DNA profiling has numerous applications. Besides its use providing evidence in criminal cases, list
four other applications of this technology.
2. DNA analysis of evidence at a crime scene matches the STR pattern of an individual in the CODIS
database but the suspect says that he did not commit the crime. He claims that it must have been his
twin sister. Explain why his argument is not valid.