Bellringer:

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Bellringer What does the term biotechnology
mean? What does the word "forensics" mean?
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Standard Students will analyze how biological
traits are passed on to successive
generations. Element Examine the use of DNA
technology in forensics, medicine, and
agriculture. EQ How is DNA technology used to
help investigators solve crimes (forensics)?
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Biotechnology

• The use of living organisms and gene science to
  develop new products and new technologies to
  sustain life, fight crime and disease, and
  improve the environment.
• Provides improved food products.
• Provides medical advances to treat disease.
• Enhances the environment by providing new ways to
  prevent pollution and clean chemical and oil
  spills.

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DNA forensics is the use of DNA to investigate
criminal and legal matters. Every person (except
identical twins) has a unique DNA sequence. So,
samples of DNA can be compared to see if they
came from the same person. These samples are
cut, sorted, and tagged to produce a pattern of
banding called a DNA fingerprint. DNA
fingerprints are now used to confirm the identity
of criminals, family members or dead bodies.
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DNA Fingerprinting
http//www.biotechnologyonline.gov.au/popups/int_d
naprofiling.html
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Cutting the DNA into manageable fragments (the
bands on the DNA fingerprint) Restriction
enzymes recognize a specific sequence of DNA.
The enzymes will cut DNA strands at all such
sites. For example, whenever a restriction
enzyme finds the DNA sequence G A A T C, it
will cut the DNA between the G and the
A. Different restriction enzymes cut DNA at
different sequences, so scientists can use them
like scissors to cut a very long strand into
smaller pieces.
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Gel Electrophoresis After the DNA is cut with
Restriction Enzymes, then it placed in a gel and
an electric current is run through it. Since DNA
is negatively charged, it will migrate down the
gel to the positively charged end.
Negative (-)
Positive ()
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Gel electrophoresis The Shorter DNA fragments
will move faster through the gel than the longer
fragments. The result is a lane of fragments
sorted by length. This method creates a DNA
fingerprint that is unique to each person.
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ELECTROPHORESIS
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Gel electrophoresis
Victim DNA
Attacker DNA
Suspect 1
Suspect 2
Suspect 3
Suspect 4
Control
Which suspect is probably the attacker?
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PCR- Polymerase Chain Reaction Sometimes only a
small drop of blood may be found at a crime scene
and more DNA is needed to make a fingerprint. PCR
is a process used to make many copies of a
segment of DNA. PCR imitates the normal process
of DNA replication in cells. PCR allows forensic
scientists to use very small amounts of DNA to
investigate crimes.
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PCR
The amount of DNA doubles with every cycle!
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Human Genome Project
Completed in 2003
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Benefits of Human Genome Project

• Improvements in medical prevention of disease,
  gene therapies, diagnosis techniques
• Production of useful protein products for use in
  medicine, agriculture, bioremediation and
  pharmaceutical industries.