Transcript What is Photosynthesis?

Biotechnology
CHAPTER 13
TRADITIONAL APPLICATIONS

Biotechnology is applied biology
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Modern focus on genetic engineering,
recombinant DNA technology, cloning, and
analysis of biomolecules
Traditional (historical) applications of
biotechnology date back to over 10,000 years
ago
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Use of yeast to produce beer and wine in Egypt
and Near East
Selective breeding of plants and animals
GENETIC ENGINEERING
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Genetic engineering refers to the
modification of genetic material to achieve
specific goals
GENETIC ENGINEERING
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Major goals of genetic engineering
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Learn more about cellular processes, including
inheritance and gene expression
Provide better understanding and treatment of
diseases, particularly genetic disorders
Generate economic and social benefits through
production of valuable biomolecules (vaccines,
and hormones)
Improved plants and animals for agriculture
RECOMBINANT DNA
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Genetic engineering utilizes recombinant DNA
technology
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Splicing together of genes or portions of genes from
different organisms
Recombinant DNA can be transferred to plants
and animals
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Modified animals are called transgenic or
genetically modified organisms (GMOs)
Most modern biotechnology includes manipulation
of DNA
Many natural processes recombine DNA
TRANSFORMATION
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Bacteria can naturally take up DNA from the
environment (transformation) and integrate
the new genes into the genome
(recombination)
VIRAL TRANSFER OF DNA
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Viral life cycle
1.
2.
3.
4.
Viral particle invades host cell
Viral DNA is replicated
Viral protein molecules are synthesized
Offspring viruses are assembled and break out
of the host cell
BIOTECHNOLOGY AND FORENSICS
Forensics is the science of criminal and victim
identification
 DNA technology has allowed forensic science
to identify victims and criminals from trace
biological samples
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 Genetic
sequences of any human individual are
unique
 DNA analysis reveals patterns that identify people
with a high degree of accuracy
POLYMERASE CHAIN REACTION
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Forensic technicians typically have very little
DNA with which to perform analyses
Polymerase Chain Reaction (PCR) produces
virtually unlimited copies of a very small
DNA sample
POLYMERASE CHAIN REACTION
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Forensic scientists focus on short tandem
repeats (STRs) found within the human
genome
STRs are repeated sequences of DNA within
the chromosomes that do not code for proteins
STRs vary greatly between different human
individuals
A match of 13 different STRs between suspect
and crime scene DNA virtually proves the
suspect was at the crime scene
GEL ELECTROPHORESIS
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Is a technique used to spread out different-length
DNA fragments in a mixture
Distinctive pattern of STR numbers and lengths are
fairly unique to a specific individual (forming a DNA
fingerprint)
DNA fingerprint from crime scene can be matched
with DNA fingerprint of suspect
BIOTECHNOLOGY AND AGRICULTURE
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At least three-quarters of corn, cotton, and
soybeans grown in the US are genetically modified
MANY CROPS ARE GENETICALLY MODIFIED
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Crop plants are commonly modified to improve
insect and herbicide resistance
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Herbicide resistant crops withstand applications of
weed-killing chemicals
Bt gene (from Bacillus thuringiensis bacterium) can be
inserted into plants to produce insect-killing protein in
crops
CLONING OF THE DESIRED GENE
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Modifying a plant genetically begins with
gene cloning
1.
Desired gene is first isolated from organism
containing it
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2.
3.
Desired gene may alternately be synthesized in the
laboratory
Gene is next cloned by inserting it into a plasmid
which replicates itself autonomously in bacterial
cells
Transfect the host organism.
GM PLANTS AND MEDICINES
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Medically useful genes can be inserted into
plants—examples:
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Potatoes have been engineered to produce
harmless hepatitis B virus and E. coli proteins,
stimulating an immune response when eaten
Plants could be engineered to produce human
antibodies, conferring passive immunity to
microbial infection merely by eating the plant
GM ANIMALS
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Transgenic (Genetically Modified) animals can be
engineered by incorporating genes into
chromosomes of a fertilized egg
Healthy transgenic animals are difficult to
engineer
Animals like sheep might be engineered to
produce more wool, cattle to produce more
proteins in their milk
THE HUMAN GENOME PROJECT
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Findings
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Human genome contains ~25,000 genes
New genes, including many disease-associated
genes have been discovered
Has determined the nucleotide sequence of all the
DNA in our entire set of genes, called the human
genome
The genes comprise 2% of all the DNA
THE HUMAN GENOME PROJECT
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Applications
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Improved diagnosis, treatment and cures of genetic
disorders or predispositions
Comparison of our genome to those of other
species will clarify the genetic differences that help
to make us human
DIAGNOSIS OF INHERITED DISORDERS
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Potential parents can learn if they are
carriers of a heritable disorder through
testing
Alleles for defective genes differ from
normal, functional genes in nucleotide
sequence
DISEASE TREATMENT
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Treatments using DNA technology
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Tailored medical care
Recombinant DNA to make proteins
Replacing defective genes to possibly cure a
disorder – Gene Therapy
 Curing AIDS patients by eliminating the
receptor site for the virus
 Remove stem cells from red bone marrow,
genetically repair the cells, and replace
ETHICAL ISSUES OF BIOTECHNOLOGY
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GM Organisms in Agriculture
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The goal of breeding or genetically modifying
plants or livestock is to make them more
productive, efficient, or useful
Genetic modification differs from selective
breeding (“traditional biotechnology”)
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Genetic engineering is much more rapid
Genetic engineering can transfer genes between
species
Genetic engineering can produce new genes
never seen before on Earth
GM ORGANISMS IN AGRICULTURE
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Benefits of genetically modified plants
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Transgenic crops decrease applications of pesticides,
saving fuel, labor, and money
GM plants can be sold at a lower price due to farm
savings
Genetically engineered crops can deliver greater
amounts of vitamins
 e.g. “golden rice” which
produces vitamin A
SCIENTIFIC OBJECTIONS TO GMOS
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Safety issues from eating GMOs
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Could ingestion of Bt protein in insect-resistant
plants be dangerous to humans?
Are transgenic fish producing extra growth
hormone dangerous to eat?
SCIENTIFIC OBJECTIONS TO GMOS
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Safety issues from eating GMOs
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Could GM crops cause allergic reactions?
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USDA now monitors GM foods for allergic potential
Toxicology study of GM plants (2003) concluded
that ingestion of current transgenic crops pose
no significant health dangers
SCIENTIFIC OBJECTIONS TO GMOS
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Environmental hazards posed by GMOs
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Pollen from modified plants can carry GM genes
to the wild plant population
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Could herbicide resistance genes be transferred to
weed species, creating superweeds?
Would they displace other plants in the wild, because
they would be less likely to be eaten by insects?
SCIENTIFIC OBJECTIONS TO GMOS
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Environmental hazards posed by GMOs
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Could GM fish reduce biodiversity in the wild
population if they escape?
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Reduced diversity in wild fish makes them more
susceptible to catastrophic disease outbreaks
THE HUMAN GENOME
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Should parents be given information about
the genetic health of an unborn fetus?
THE HUMAN GENOME
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Should parents be allowed to select the
genomes of their offspring?
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Embryos from in vitro fertilization are currently
tested before implantation
Many unused embryos are discarded
THE HUMAN GENOME
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Should parents be allowed to design or
correct the genomes of their offspring?