Genetics and Biotechnology

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Transcript Genetics and Biotechnology

Chapter 13
Genetics and Biotechnology
13.1 Applied Genetics
Selective Breeding
 Desired traits of certain plants and animals are
selected, and passed on to future generations.
Saint Bernard
Rescue dog
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Husky
Sled dog
German shepherd
Service dog
Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
Genetic Engineering
 manipulating the DNA of one organism in
order to insert the DNA of another organism
(exogenous DNA).
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 Genetically engineered organisms are used
 to study the expression of a particular gene.
 to investigate cellular
processes.
 to study the
development of a
certain disease.
Genetically engineered bollworm
 to select traits that might
be beneficial to humans.
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 Restriction enzymes recognize and bind to
specific DNA sequences and cleave the DNA
within the sequence.
 Scientists use restriction enzymes as powerful
tools for isolating specific genes or regions of
the genome.
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 EcoRI specifically cuts
DNA containing the
sequence GAATTC.
 The ends of the DNA
fragments, called sticky
ends, contain singlestranded DNA that is
complementary.
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 An electric current is used to separate
DNA fragments according to the size of
the fragments in a process called gel
electrophoresis.
 When an electric current is applied, the DNA
fragments move toward the positive end of
the gel.
 The smaller fragments move farther faster
than the larger ones.
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 The unique pattern
created based on the
size of the DNA
fragment can be
compared to known
DNA fragments for
identification.
Gel electrophoresis
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 The newly generated DNA molecule with DNA from
different sources is called recombinant DNA.
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 To make a large quantity of recombinant plasmid DNA,
bacterial cells are mixed with recombinant plasmid DNA.
 Some of the bacterial cells take up the recombinant
plasmid DNA through a process called transformation.
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 Large numbers of identical bacteria, each
containing the inserted DNA molecules, can be
produced through a process called cloning.
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
Biotechnology
 Organisms that have a gene from another
organism inserted into them are called
transgenic organisms.
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Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
Examples of Transgenic Plants:
 Genetically engineered cotton resists insect
infestation of the bolls.
 Sweet-potato plants are resistant to a virus
that could kill most of the African harvest.
 Rice plants with increased iron and vitamins
could decrease malnutrition.
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Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
The Human Genome Project
 The goal was to determine the sequence of
the approximately three billion nucleotides that
make up human DNA and to identify all of the
approximately 20,000–25,000 human genes.
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Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
Sequencing the Genome
 Each of the 46 human chromosomes was
cleaved.
 These fragments were combined with vectors
to create recombinant DNA, cloned to make
many copies, and sequenced using automated
sequencing machines.
 Computers analyzed the overlapping regions
to generate one continuous sequence.
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Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
 Decoding the
sequence of the
human genome can
be compared to
reading a book that was printed in code.
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Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
 Less than two percent of the nucleotides in the
human genome code for all the proteins in the
body.
 The genome is filled with long stretches of
repeated sequences that have no direct
function. These regions are called noncoding
sequences.
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Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
DNA Fingerprinting
 Protein-coding regions of DNA are almost
identical among individuals.
 The long stretches of noncoding regions of
DNA are unique to each individual.
 DNA fingerprinting involves separating these
DNA fragments to observe the patterns that are
unique to every individual.
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