GENETIC TECHNOLOGY

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Transcript GENETIC TECHNOLOGY

GENETIC MUTATIONS
 GENE MUTATIONS
 Change/mistake with
individual gene
 Point Mutation – 1
amino acid is changed
 Frameshift Mutation –
an amino acid is added
or deleted
GENETIC MUTATIONS
 CHROMOSOMAL MUTATIONS
 Mistakes affect the entire chromosome
 Deletion: lose part of chromosome
 Duplication: gain extra parts on a chromosome
GENETIC MUTATIONS
 Inversion: rearrangement of the chromosome
 Translocation: genes are rearranged btw 2 different
chromosomes
GENETIC MUTATIONS
 Nondisjunction: chromosomes do NOT separate during
meiosis  results in polyploidy (too many
chromosomes)
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Cause of many different genetic diseases
 Down’s, Klinefelter, Turner’s, Triple X, XYY
DIAGNOSING GENETIC DISEASES
 GENETIC COUNSELORS
 Research family history to determine parents’ risk of
passing genetic disorders to their children
 Typically used by couples with family history of genetic
disorders
DIAGNOSING GENETIC DISEASES
 GENETIC TESTING
 Carrier Recognition – parents can be tested to see if
carry genes for genetic disorder
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(Tay-Sachs, cystic fibrosis, sickle-cell anemia)
 Fetal Testing – test unborn child for genetic disorders
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Remove fetal tissue
Allow cells to multiply in the lab
Magnify & photograph chromosome spread
Create a karyotype – map of chromosomes
NORMAL KARYOTYPES
MALE
FEMALE
DIAGNOSING GENETIC DISEASES
 Types of Fetal Tests:
 Amniocentesis (15-20 wks) – remove amniotic fluid from mother
 Fluid tested for chemical indicators or used create karyotype
 CVS - Chorionic Villus Sampling (8-10 wks)
 Remove tissue from placenta – more immediate results
 Ultrasound – looks for major structural abnormalities
 Fetoscopy – insert fiber optic scope into uterus to examine fetus for
major abnormalities
DNA FINGERPRINTS
 DNA can be collected from any living tissue
 (blood, skin, hair, urine, semen, sweat or tears)
 Gel Electrophoresis
 DNA sample is inserted into a “gel”
 An electric current is passed through the gel
 Shorter strands move farther down the gel as pieces of
DNA separate & show up as bands
 Gel is stained to make the bands more visible
 Samples are compared to find a match
DNA FINGERPRINTS
DNA FINGERPRINTS
Human Genome Project
 Map all the genes on the 46 human chromosomes
 Information has led to many advances in the fields of
medicine, agriculture, bio-engineering
GE – WHAT IS IT?
 Removing genes from one organism and inserting
them in another
GE – HOW DO THEY DO IT?
RESTRICTION ENZYMES
• Naturally occur in
bacteria – used cut up
foreign DNA (form of
protection)
• Cut DNA fragments are
called “sticky ends”
• S. ends of DNA
fragments can be joined
in a lab to produce
recombinant DNA (mix
of DNA)
GE – WHAT CAN IT DO?
PROS
 Disease resistant crops
 New vaccines &
medications (insulin)
 Bigger livestock more
meat, milk, wool etc.
CONS
 Unpredictable 
technology is new & no
guarentee that products
free of side affects
 $$  companies patent
genes & demand high
prices
GENE THERAPY
 Replace defective genes
w/ normal or functional
genes
 When cells reproduce 
normal gene will also be
replicated
 Most suitable for single
gene mutations
 Enzyme deficiencies
SOMATIC CELL THERAPY
 Somatic cells = body cells
 Mutated cells removed
 Corrected gene inserted
 “New” cells returned
 Affects only the
individual receiving
treatment
 Temporary cure – cells
die off
STEM CELL THERAPY
 Stem cell = basis all
future cells
 Found embryo, chord
blood & bone marrow
 May provide broader,
more long-lasting
treatment
 Not currently safe or
100% effective
GERM CELL THERAPY
 Germ cells = gametes
 Replace or remove
defective genes in
sperm/egg cells prior to
fertilization
 Affect future generations
 Permanent solution
 Successful in mice &
primates
 Social & Ethical Issues
 Are humans next?
 Who should have access
to this technology?
 Are we playing God?
 If we can fix disorders,
what else could we fix?
 Where do we draw the
line – what is too much?