Download Genetic Engineering

Genetic Engineering
Chapter 5
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Genetic engineering: the alteration of the
genetic components of organisms by
human intervention.
Mutations
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Variations from the normal genetic
makeup of an organism
A gene mutates or changes and a new
characteristic is made
Also called genetic accidents
Organism usually dies from mutations
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Missing a limb, too many limbs, organ defects
etc.
Mutations continued
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Not all mutations are bad
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Seedless watermelon
Polled (no horned) Hereford cattle
A farmer noticed that some of his cattle that
were born, naturally did not have any horns
 He bought other polled Herefords from other
farmers and started a new breed of cattle
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Yellow Delicious apples
Original color is red
 A farmer noticed that there were yellow apples
on his red delicious apple tree
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DNA
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DNA: deoxyribonucleic acid
Makes up chromosomes
Different segments of a chromosome
controls a different trait that is
expressed in an organism
DNA is shaped like a double-helix or a
twisted ladder
Discovered by Watson and Creek
DNA continue
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Made up of nitrogen base pairs that
connect the two strands
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A-adenine
T-thymine
G- guanine
C- cytosine
A always pairs up with T
G always pairs up with C
Gene Mapping
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Finding the location of certain genes on
chromosomes
The arrangement of the nitrogen base
pairs (A,T,C and G) determines what an
organism looks like
Human Genome Project
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Trying to find where certain traits are located
in humans’ DNA (Alzheimer's, diabetes, etc.)
Gene Splicing
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Once the DNA sequence is found,
enzymes are added to separate the two
strands at a certain location
Other DNA can be inserted into the
location and the original DNA is taken out
First gene splicing was done with bacteria
Gene Splicing continued
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First use of gene splicing was to make
human insulin for diabetics
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Insulin was harvested from the pancreas of
cattle that were slaughtered
Very expensive- only a little amount of insulin
was obtained from cattle
Some people were allergic to this type of
insulin
Used E. coli bacteria- reproduce quickly and
could pass on the insulin making gene to
their offspring
Gene Splicing continued
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BST- bovine somatotropin
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Naturally occurring hormone in cattle that
increases the production of milk
Helps the cow produce less fat and more milk
E. coli bacteria used again
Tissue Culture- regenerating plants from a
single cell
Gene Splicing continued
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Round-Up ready corn (round up won’t kill
the corn plants, but will kill all other
plants)
Resistance to certain insects and diseases
Scientists spliced DNA from fireflies into a
tobacco plant, which resulted in a plant
that could glow in the dark
Future: naturally colored cotton?
Transgenetic
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Transferring genetic material between
different types of organisms
Done shortly after an egg was fertilized by
sperm
Adding growth genes of humans into mice
Adding the glowing genes of fireflies into
plants
Societal Concerns
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Why geneticially altered food?
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More people = less land to raise food
Ownership of the genetically altered
organisms
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Companies will spend millions of dollars
Some believe that no one should have
ownership of genetic materials- especially
human
Societal concerns continued
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Effects on the environment
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Kudzu
Genetically altered fish
Are genetically altered organisms safe to
eat?
Should humans be “playing God”?
Regulation of Genetic
Engineering
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USDA- United States Department of
Agriculture
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Strict guidelines for testing genetically altered
organisms
APHIS- Animal and Plant Health Inspection
Service
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Enforces the regulations that the USDA set