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Chapter 12 Assessment
How could manipulating DNA be
beneficial?
Chapter 13
Genetics and Biotechnology
Selective Breeding
 The process by which desired traits of certain plants
and animals are selected and passed on to their
future generations is called selective breeding.
Saint Bernard
Rescue dog
Husky
Sled dog
German shepherd
Service dog
Chapter 13
Genetics and Biotechnology
Hybridization
 Hybrid organisms can be bred to be more
disease-resistant, to produce more offspring,
or to grow faster.
 A disadvantage of hybridization is that it is
time consuming and expensive.
Chapter 13
Genetics and Biotechnology
13.1 Applied Genetics
Inbreeding
 The process in which two closely related
organisms are bred to have the desired traits
and to eliminate the undesired ones in future
generations
 Pure breeds are maintained by inbreeding.
 Disadvantage - harmful recessive traits also
can be passed on to future generations.
Chapter 13
Genetics and Biotechnology
13.1 Applied Genetics
Test Cross
 A test cross involves
breeding an organism
that has the unknown
genotype with one that is
homozygous recessive
for the desired trait.
Chapter 13
Genetics and Biotechnology
Genetic Engineering
 Technology that involves manipulating
the DNA of one organism in order to insert
the DNA of another organism.
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.
Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
DNA Tools
 An organism’s genome is the total DNA in
the nucleus of each cell.
 DNA tools can be used to manipulate DNA
and to isolate genes from the rest of the
genome.
Chapter 13
Genetics and Biotechnology
 Restriction enzymes recognize and bind to
specific DNA sequences and cleave the DNA
within the sequence.
 Scientists use restriction enzymes to isolate
specific genes or regions of the genome.
Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
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.
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
Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 The newly generated DNA molecule with DNA from
different sources is called recombinant DNA.
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.
Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
 A technique called the polymerase chain
reaction (PCR) can be used to make millions
of copies of a specific region of a DNA
fragment.
PCR Analysis
Chapter 13
Genetics and Biotechnology
13.2 DNA Technology
Biotechnology
 Organisms, genetically engineered by inserting
a gene from another organism, are called
transgenic organisms.
 Scientists produce most transgenic animals
in laboratories for biological research.
Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
The Human Genome Project
 The goal of the Human Genome Project
(HGP) 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.
Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
 Less than two percent of all 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.
Chapter 13
Genetics and Biotechnology
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 distinct banding
patterns that are unique to every individual.
Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
DNA Microarrays
 Tiny microscope slides or silicon chips that
are spotted with DNA fragments
 Help researchers determine whether the
expression of certain genes is caused by
genetic factors or environmental factors.
Visualizing
Microarray
Analysis
Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
 Variations in the DNA sequence that occur
when a single nucleotide in the genome is
altered are called single nucleotide
polymorphisms or SNPs.
Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
 The study of how genetic inheritance
affects the body’s response to drugs is
called pharmacogenomics.
 The benefits of pharmacogenomics include
more accurate dosing of drugs that are safer
and more specific.
Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
 A technique aimed at correcting mutated genes
that cause human diseases
is called gene therapy.
 Scientists insert a normal
gene into a chromosome
to replace a dysfunctional
gene.
 Genomics is the study of an organism’s genome.
Chapter 13
Genetics and Biotechnology
13.3 The Human Genome
 Genes are the primary information storage
units, whereas proteins are the machines of
a cell.
Quiz
• Analyze how DNA technology is used in
forensics, agriculture, and medicine.