Download Chapter 11 - Jamestown Public Schools

Chapter 11
Gene Technology
Section 1: Genetic Engineering
Section 2: Human Applications of Genetic
Engineering
Section 3: Genetic Engineering in
Agriculture
Section 1
Genetic Engineering
Objectives:
•Describe four basic steps commonly used in genetic
engineering experiments.
•Evaluate how restriction enzymes and the antibiotic
tetracycline are used in genetic engineering.
•Relate the role of electrophoresis and probes in
identifying a specific gene.
Section 1
Genetic Engineering
Basic Steps of Genetic Engineering
•Genetic Engineering Genetic engineers manipulate
DNA for practical purposes.
•Restriction Enzymes Restriction enzymes cleave
DNA into fragments that have short sticky ends.
• Steps in a Genetic Engineering Experiment (1)
Cut DNA, (2) Recombinant DNA is produced, (3)
The gene is cloned, and (4) Cells are selected and
screened for gene of interest.
Section 1
Genetic Engineering
Basic Steps of Genetic
Engineering continued
•Cutting DNA and Making Recombinant DNA
Restriction enzymes are used to generate sticky ends.
Sticky ends allow DNA fragments from different
organisms to join together to form recombinant DNA.
•Cloning, Selecting, and Screening Cells
Recombinant DNA is inserted into host cells. Each
time the cells reproduce, the gene of interest is cloned.
The cells are then screened to identify cells that have
the recombinant DNA.
Section 1
Genetic Engineering
Confirmation of a Cloned Gene
•Gel Electrophoresis Electrophoresis uses an electric
field within a gel to separate DNA fragments by their
size.
•Identifying a Gene of Interest Specific genes can
be identified with DNA or RNA probes using the
Southern blot technique.
Section 2
Human Applications of Genetic Engineering
Objectives:
•Summarize two major goals of the Human Genome
Project.
•Describe how drugs produced by genetic
engineering are being used.
•Summarize the steps involved in making a
genetically engineered vaccine.
•Describe how gene therapy is being used to try to
cure genetic disorders.
•Identify two different uses for DNA fingerprints.
Section 2
Human Applications of Genetic Engineering
The Human Genome Project
•Human Genome Project The Human Genome
Project is an effort to determine the nucleotide
sequence of and map the location of every gene on
each human chromosome. The sequence of the
genomes of many organisms has already been
determined.
•The Geography of the Genome Large amounts of
DNA do not encode for proteins.
•The Number of Human Genes Human cells
contain only about 30,000 to 40,000 genes.
Section 2
Human Applications of Genetic Engineering
Genetically Engineered Drugs and Vaccines
•Drugs Genetic engineering is used to manufacture
human proteins for use as drugs.
•Vaccines Genetic engineering is used to
manufacture human proteins for making safer and
more effective vaccines.
Section 2
Human Applications of Genetic Engineering
DNA Fingerprinting
•DNA Fingerprinting DNA fingerprinting is used to
identify individuals and determine relationships
between individuals.
Section 3
Genetic Engineering in Agriculture
Objectives:
•Describe three ways in which genetic engineering
has been used to improve plants.
•Summarize two ways in which genetic engineering
techniques have been used to modify farm animals.
•Summarize the cloning of sheep through the use of
differentiated cells.
Section 3
Genetic Engineering in Agriculture
Improving Crops
•Better Crops Crop plants can be genetically
engineered to have favorable characteristics,
including improved yields and resistance to
herbicides and destructive pests.
•More Nutritious Crops Genetic engineers have
been able to improve the nutritional value of crop
plants, such as rice enriched with iron and vitamin A.
Section 3
Genetic Engineering in Agriculture
Risks of Genetically Modified Crops
•Potential Problems There may be unforeseen
negative effects of using genetically modified crops
such as producing herbicide resistant crops and
allergy problems.
•Are GM Crops Harmful to the Environment?
The possibility of GM crop genes being introduced to
other organisms poses a potential risk.
Section 3
Genetic Engineering in Agriculture
Gene Technology in Animal Farming
•Improving or Modifying Farm Animals
Genetically engineered growth hormone increases
milk production in dairy cows and weight gain in
cattle and hogs.
•Making Medically Useful Proteins Transgenic
animals have foreign DNA introduced to their cells.
For example, introducing medicinal human genes to
farm animals can lead to the production of vital
human proteins in animals’ milk.
Section 3
Genetic Engineering in Agriculture
Gene Technology in
Animal Farming continued
•Cloning From Adult Animals The cloning of farm
animals using differentiated cells was accomplished
in 1997. In addition, transgenic animals can be cloned
and used to make proteins that are useful in medicine.
Section 3
Genetic Engineering in Agriculture
Problems With Cloning
•Developmental Problems Problems in cloning lie
within a developmental process that conditions eggs
and sperm so that the right combination of genes
are turned “on” or “off” during development.
•The Importance of Genomic Imprinting In
genomic imprinting, chemical changes made to
DNA prevent a gene’s expression without altering
its sequence. This allows for control over gene
expression in clones.
Section 3
Genetic Engineering in Agriculture
Problems With Cloning continued
•Why Cloning Fails Problems in
development related to genomic imprinting
can lead to technical problems in cloning.