.Name: Date:
Student Exploration: DNA Profiling
Vocabulary: DNA polymerase, DNA profiling, gel electrophoresis, gene, mutation, non-coding
region, polymerase chain reaction, primer, short tandem repeat
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
In 1985, Darryl Hunt was convicted of murder. While Hunt was in jail, a new method for
analyzing DNA evidence was invented. The DNA evidence on the victim did not match Hunt’s
DNA but did match that of another prisoner. After 19 years spent behind bars, Hunt was finally
declared innocent and released from prison in 2004.
m
er as
1. DNA is used to tell people apart. What aspects of DNA do you think make this possible?
co
eH w
I think that DNA can be used to tell people apart based on humans DNA sequences or the
o.
lengths of repeated regions of DNA.
rs e
ou urc
2. What are some possible uses for technology that can identify people based on their DNA?
o
Some possible uses for technology that can identify people based on their DNA could be
aC s
fingerprinting or cloning.
vi y re
Gizmo Warm-up
ed d
DNA profiling does not just compare people’s entire genome side
ar stu
by side. Instead, a very particular part of the DNA is compared. In
the DNA Profiling Gizmo you will learn about the differences in
DNA that make DNA profiling possible and you will use that
knowledge to design your own DNA profiling test.
is
Click on the crime lab in the Forensic training section. You are looking at a strand of DNA. DNA
Th
contains genes and non-coding regions between genes. Click on Non-coding A.
1. You are looking at a portion of the non-coding A section for three different people. Are these
sh
sections the same or different? Explain.
They are different because the number of sequences called STRs varies between the 3
people
2. Click Previous then click on Gene A. Are there differences in gene A for the three people?
This study source was downloaded by 100000829725281 from CourseHero.com on 08-16-2021 16:54:20 GMT -05:00
https://www.coursehero.com/file/60240192/DNAProfilingSE-COMPLETEDdocx/
, Yes, Person 2 is different from Person1 and Peron 3.
Activity A: Get the Gizmo ready:
Forensic training ● Click on Forensic training and Start again.
Introduction: In this activity, you will learn about the principles and techniques that make DNA
profiling possible. Genes code for specific traits. In people, the DNA sequences for most genes
are nearly identical, since any change could result in a harmful disorder. The areas between
genes do not code for any essential traits, so a change to the DNA sequence doesn’t have any
major consequences. As a result, these regions tend to be very different for different people.
Question: How can the differences in DNA be exploited to perform DNA profiling?
1. Observe: Click on non-coding A. What do you see in the middle of each of the three DNA
m
sequences? I see short tandem repeats or STRs
er as
co
eH w
2. Compare: Turn on Show short tandem repeats (STRs). An STR is a short, repeated
o.
rs e
sequence of DNA, like TAAA. They can be repeated any number of times without affecting
ou urc
the traits of the person. Different people usually have different numbers of repeats.
o
What does this do to the length of each person’s non-coding regions?
aC s
vi y re
It makes each person's non-coding regions differ in length, some longer than
others while some shorter.
ed d
ar stu
3. Create: Your goal is to make copies of the STR region. To do this, you will make primers
that surround the STR region. A primer is a short sequence of DNA that acts as a starting
point for DNA replication.
is
Click Next. Click on person 1’s DNA to separate the two strands. Drag along the AAGGC
nucleotides, and then the TCGCC nucleotides to create primers. Click Next. The Gizmo will
Th
add the same primers to the two other people.
What do you notice about where the primers attach in each person?
sh
There is one primer attached to the top of the DNA strand and the other attached to the
bottom DNA strand at each end of the sample, the primers bind to complimentary
sequences.
This study source was downloaded by 100000829725281 from CourseHero.com on 08-16-2021 16:54:20 GMT -05:00
https://www.coursehero.com/file/60240192/DNAProfilingSE-COMPLETEDdocx/
Student Exploration: DNA Profiling
Vocabulary: DNA polymerase, DNA profiling, gel electrophoresis, gene, mutation, non-coding
region, polymerase chain reaction, primer, short tandem repeat
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
In 1985, Darryl Hunt was convicted of murder. While Hunt was in jail, a new method for
analyzing DNA evidence was invented. The DNA evidence on the victim did not match Hunt’s
DNA but did match that of another prisoner. After 19 years spent behind bars, Hunt was finally
declared innocent and released from prison in 2004.
m
er as
1. DNA is used to tell people apart. What aspects of DNA do you think make this possible?
co
eH w
I think that DNA can be used to tell people apart based on humans DNA sequences or the
o.
lengths of repeated regions of DNA.
rs e
ou urc
2. What are some possible uses for technology that can identify people based on their DNA?
o
Some possible uses for technology that can identify people based on their DNA could be
aC s
fingerprinting or cloning.
vi y re
Gizmo Warm-up
ed d
DNA profiling does not just compare people’s entire genome side
ar stu
by side. Instead, a very particular part of the DNA is compared. In
the DNA Profiling Gizmo you will learn about the differences in
DNA that make DNA profiling possible and you will use that
knowledge to design your own DNA profiling test.
is
Click on the crime lab in the Forensic training section. You are looking at a strand of DNA. DNA
Th
contains genes and non-coding regions between genes. Click on Non-coding A.
1. You are looking at a portion of the non-coding A section for three different people. Are these
sh
sections the same or different? Explain.
They are different because the number of sequences called STRs varies between the 3
people
2. Click Previous then click on Gene A. Are there differences in gene A for the three people?
This study source was downloaded by 100000829725281 from CourseHero.com on 08-16-2021 16:54:20 GMT -05:00
https://www.coursehero.com/file/60240192/DNAProfilingSE-COMPLETEDdocx/
, Yes, Person 2 is different from Person1 and Peron 3.
Activity A: Get the Gizmo ready:
Forensic training ● Click on Forensic training and Start again.
Introduction: In this activity, you will learn about the principles and techniques that make DNA
profiling possible. Genes code for specific traits. In people, the DNA sequences for most genes
are nearly identical, since any change could result in a harmful disorder. The areas between
genes do not code for any essential traits, so a change to the DNA sequence doesn’t have any
major consequences. As a result, these regions tend to be very different for different people.
Question: How can the differences in DNA be exploited to perform DNA profiling?
1. Observe: Click on non-coding A. What do you see in the middle of each of the three DNA
m
sequences? I see short tandem repeats or STRs
er as
co
eH w
2. Compare: Turn on Show short tandem repeats (STRs). An STR is a short, repeated
o.
rs e
sequence of DNA, like TAAA. They can be repeated any number of times without affecting
ou urc
the traits of the person. Different people usually have different numbers of repeats.
o
What does this do to the length of each person’s non-coding regions?
aC s
vi y re
It makes each person's non-coding regions differ in length, some longer than
others while some shorter.
ed d
ar stu
3. Create: Your goal is to make copies of the STR region. To do this, you will make primers
that surround the STR region. A primer is a short sequence of DNA that acts as a starting
point for DNA replication.
is
Click Next. Click on person 1’s DNA to separate the two strands. Drag along the AAGGC
nucleotides, and then the TCGCC nucleotides to create primers. Click Next. The Gizmo will
Th
add the same primers to the two other people.
What do you notice about where the primers attach in each person?
sh
There is one primer attached to the top of the DNA strand and the other attached to the
bottom DNA strand at each end of the sample, the primers bind to complimentary
sequences.
This study source was downloaded by 100000829725281 from CourseHero.com on 08-16-2021 16:54:20 GMT -05:00
https://www.coursehero.com/file/60240192/DNAProfilingSE-COMPLETEDdocx/
