Genetic Engineering
• Genetic Engineers
can alter the DNA
code of living
organisms.
• Selective Breeding
• Recombinant DNA
• Transgenic
Organisms
• Cloning
Selective Breeding
• Breed only those
plants or animals with
desirable traits
• People have been
using selective
breeding for 1000’s
of years with farm
crops and
domesticated
animals.
Genetic Engineering
• Is the process of changing an organism’s DNA
(genes), usually by inserting a new gene from
another organism.
Recombinant DNA
• The ability to combine
the DNA of one
organism with the
DNA of another
organism.
• Recombinant DNA
technology was first
used in the 1970’s
with bacteria.
Recombinant Bacteria
1.
Remove bacterial DNA (plasmid).
2.
Cut the Bacterial DNA with
restriction enzymes.
3.
Cut the DNA from another
organism with restriction
enzymes.
4.
Combine the cut pieces of DNA
together with another enzyme
and insert them into bacteria.
5.
Reproduce the recombinant
bacteria.
6.
The foreign genes will be
expressed in the bacteria.
Some Benefits of Recombinant
Bacteria
1. Bacteria can make human insulin or
human growth hormone.
1. Bacteria can be engineered to “eat” oil
spills.
The DNA of plants and animals
can also be altered.
PLANTS
1. disease-resistant
and insect-resistant
crops
2. Hardier fruit
3. 70-75% of food in
supermarket is
genetically modified
organisms (GMOs).
video
Creating a Genetically
Modified Plant
What do you think about eating
genetically modified foods?
Genetically modified organisms are
called transgenic organisms.
TRANSGENIC ANIMALS
1.
Mice – used to study
human immune system
2.
Chickens – more
resistant to infections
3.
Cows – increased milk
supply and leaner meat
4. Goats, sheep and pigs –
produce human proteins
in their milk
Transgenic Goat
.
Human DNA in
a Goat Cell
This goat contains a human
gene that codes for a blood
clotting agent. The blood
clotting agent can be
harvested in the goat’s milk.
Creating a
Transgenic
Animal
DNA for the
desired trait is
added to an egg
cell, and the egg
is implanted in the
female animal.
Transgenic
animals
Transgenic plants
Cloning
What are clones?
Genetically Identical Copies
Clones sometimes occur
naturally…
• Identical twins are clones of each other
Sperm cell
Baby
fertilization
splits
Fertilized egg cell
Egg cell
Baby
Identical Twins
• Clones of each other but not of their parents
But now we can create clones in a
laboratory.
Dolly The Sheep
Dolly was the first
mammal cloned from
an adult cell.
She was born in 1996
and died in 2003.
She was 6 when she
died, about half the
usual age for a sheep.
Making
Dolly the
sheep
1. Remove egg
from
surrogate
mother, take
out nucleus.
Udder
2. Take cell
from animal to
be cloned, put
in egg cell.
3. Zap egg
with
electricity.
4. Implant egg
(embryo) in
surrogate
mother.
Recently cloned animals
Problems with cloning mammals
• Dolly developed premature arthritis and
showed signs of aging too quickly.
• She died at age 6, which is half the natural
age of a sheep.
• Other cloned animals have experienced
problems such as breathing trouble,
growing too large, and a shorter life span.
Some Pros for Cloning
• Cloning can be used to produce organs
and tissues to help treat health problems
such as arthritis, MS (Multiple Sclerosis),
kidney failure, heart failure, spinal injuries,
diabetes, and Parkinson's disease.
• Cloning could be an option in the future
for women who cannot conceive a child.
•Cloning could be used to bring back extinct
or endangered animals.
Ethical Questions to consider…
• Should humans be cloned?
• Is cloning safe? Is it necessary? Is it wise?
Some Ethical Concerns
• Could cloning change human evolution in a
negative way?
• Would human clones be treated as objects
rather than people?
• Would we be tempted to genetically modify &
enhance the DNA of cloned people?
• Would people use clones to harvest
replacement organs?
Websites to Explore
http://www.mnn.com/green-tech/research-innovations/photos/12-bizarre-examples-ofgenetic-engineering/mad-science
What is genetic engineering and many good basics
http://www.ucsusa.org/food_and_environment/genetic_engineering/what-is-genetic-engineering.html
Designer Seeds – Read this and be a pro about genetic engineering.
http://www.beyonddiscovery.org/content/view.page.asp?I=1230
Pros and Cons PDF
http://www.pbs.org/now/classroom/geneteachers.pdf
Genetic Engineering in the news
http://topics.nytimes.com/top/news/science/topics/genetic_engineering/index.html?excamp=GGGNgen
eticengineering
Recommended! Debate over Genetically-modified foods
http://www.actionbioscience.org/biotech/sakko.html
Websites to Explore
Good questions and answers in the debate
http://www.foodfuture.org.uk/home.aspx
The Resistance
http://www.geaction.org/
Genetically modified foods health concern – great detail
http://www.actionbioscience.org/biotech/pusztai.html
Impacts on Ecology –great detail
http://www.actionbioscience.org/biotech/altieri.html
Biotechnology and the Green Revolution – Dr. Borlaug won a Nobel prize for his work with
genetic engineering. Read an interview with him.
http://www.actionbioscience.org/biotech/borlaug.html#Primer
Written transcript from a TV show about genetically engineered plants
http://www.pbs.org/now/transcript/transcript_corn.html