Transcript Advances in Genetics

ADVANCES IN GENETICS
Key Concepts
•What are three ways of
producing organisms with
desired traits?
•What is the goal of the Human
Genome Project?
KEY TERMS
Selective breeding
 Inbreeding
 Hybridization
 Clone
 Genetic engineering
 Gene therapy
 genome
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SELECTIVE BREEDING
One of 3 methods used to
develop organisms with
desirable traits
 Select organisms with
desirable traits to be parents of
next generation
 Ex: Corn, dogs
 Two selective breeding
techniques are inbreeding and
hybridization
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INBREEDING
Crossing 2 individuals that have
similar characteristics
 Ex. Crossing 2 turkeys that are
both plump and grow quickly- offspring are likely
to have both those desirable qualities
 Inbred organisms have alleles that are very similar
to parents
 Inbred organisms are genetically very similar so
they may inherit alleles that lead to genetic
disorders
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HYBRIDIZATION
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Breeders cross 2 genetically
different individuals
Hybrid that results is bred to
have best traits from both
parents
Ex. Crossing one type of corn
with large kernels with
another that is resistant to
disease. Result might be
hybrid corn with both of the
desired traits
CLONING
Clone – an organism that has exactly the same
genes as the organism from which it was
produced
 Easy to clone many plants – cut a stem, put it
in soil and water, and it will develop into a new
plant – genetically the same as the parent
 Researchers have been cloning animals such
as sheep, cows, goats and pigs
 Click and Clone
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GENETIC ENGINEERING
Genes from one organism are transferred into
the DNA of another organism
 Used to produce medicines and improve food
crops
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GENETIC ENGINEERING IN BACTERIA
Used to produce insulin
 Bacteria has 1 DNA molecule in the cytoplasm
 Also has small circular pieces of DNA called plasmids
 Scientists insert a human gene into the plasmid
 The bacteria and all its offspring will now make the
protein that this gene codes for –in this case insulin
 Since bacteria reproduce very
quickly, large amounts of insulin
can be produced
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GENETIC ENGINEERING IN OTHER ORGANISMS
Can use technique to insert genes into other
animals
 Human genes can be inserted into the cells of
cows – The cows will produce the protein for which
the gene codes in their milk
 This has been used to produce the blood clotting
protein needed by people with hemophilia
 Genes have also been inserted into plants to help
them survive in cold temperatures and resist
insect pests
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GENE THERAPY
Using genetic engineering to correct genetic
disorders
 Involves inserting copies of a gene directly into
a person’s cells
 Ex. To treat hemophilia, doctors would replace
the defective allele on the X chromosome so
the person’s blood would clot normally
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GENE THERAPY
HURDLES FOR GENE THERAPY
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First, scientists must find the best way to correct
the genetic defect that is causing the disorder
Correct or increase the defective cell product
 Make diseased cells weaker
 Block operation of diseased cells
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Second – scientists must find a way to carry the
genetically engineered DNA to target cells
Viruses are an excellent candidate to deliver the genes
because they infect living cells
 Virus must be genetically engineered to render it
harmless
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CONCERNS ABOUT GENETIC ENGINEERING
Some people are concerned about long-term
effects of genetic engineering
 Ex. Are genetically modified foods safe?
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Concerns that they may harm the environment or cause
health problems in humans
Scientists are trying to address these concerns
and learn more about the effects of genetic
engineering
LEARNING ABOUT HUMAN GENETICS
The Human Genome Project
 Genome – all the DNA in
one cell of an organism
 Main goal of Human
Genome Project has been
to identify the DNA
sequence of every gene in
the human genome
 Completed first draft found that we have at
least 30,000 genes.
Average gene has 3,000
bases
DNA FINGERPRINTING
DNA technology can be used
to identify people and show
relationships
 DNA is broken down into small fragments.
Selected fragments are used to produce a
pattern similar to a fingerprint
 Except for identical twins no 2 people have the
same DNA fingerprint
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SOURCES
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http://www.energy-dimension.com/12-bizarreexamples-of-genetic-engineering/