Transcript Genetic_Engineering

Genetic Engineering
Unit
Chapter 15
Slide # 2
Genetic engineering:
changing an organism’s DNA
to make it more beneficial to
humans
Ex: different types of
chili peppers
Slide # 3
A. Selective Breeding
1. Selecting individuals with
the desired traits to
produce new offspring
a. Used in agriculture to
produce superior plant
species
b. Used to produce breeds of
domestic animals – dogs,
horses, cattle
2. Also called artificial
selection
All of the different
plants produced from
wild mustard by
selective breeding!
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B. Limits of Selective Breeding
1.All of the organism’s genes
are passed on – even
undesirable traits
2. Ex: Might want plants
that are drought resistant;
however, end up with
plants that don’t produce
many seeds!
When breeding for drought
resistance, instead of getting
ears of corn like on the left,
you might end up with ears
of corn like on the right!
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C. Types of Selective Breeding
1.Inbreeding: organisms are crossed
with individuals that have similar
traits.
– Preserves well adapted genotypes
- In plants, insures pollination w/out
insects
– Decreases genetic variation
(differences)
Self-pollination is a
form of inbreeding.
Slide # 6
2.Hybridization: crossing 2
dissimilar, but related
organisms
- Usually stronger/hardier than
parents – known as hybrid
vigor
- May promote the loss of
native species
1. African catfish (left) grows
faster than Thai catfish.
2. Thai catfish (middle) has
better tasting flesh than
African catfish.
3. Hybrid (right) grows fast &
has good tasting flesh.
Check out animation on wiki
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D. Recombinant DNA
1. Definition: made from pieces of DNA from
different organisms; the pieces ‘stick’ together
- DNA from different organisms are “recombined”
2. How it is made:
–Two DNA molecules are ‘cut’ by restriction
enzymes (‘biological scissors’)
–DNA fragments are then joined together by DNA
ligase
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E. Transgenic Organisms: Plants
1.Definition: any organism
that has genes from a
different organism
inserted into its DNA.
2.New & different
genomes could be
produced
a.EX: genetically
engineering ‘golden
rice’ provides vitamin
A (could prevent
childhood blindness)
The rice on the right is called golden
rice. Its genome contains the gene for
producing vitamin A from daffodils.
This rice is healthier for people who do
not get enough vitamin A in their diets.
Slide # 10
F. Transgenic Organisms: Animals
1.Genetically engineered mice used
in cancer research:
a.Contain gene from glowing
jellyfish
b.Glow when a cancer is growing
in them
c.Mice are given chemotherapy
drugs; if the tumor shrinks,
they glow less & less
2.Mice don’t die from cancer or drugs
LINK
(gene)
Mice expressing “glow”
gene from jellyfish.
Glowing jellyfish
G. Gene Therapy
the process of changing a gene to treat a
genetic disorder
 A faulty gene is replaced by a normal one
 Currently a high-risk experimental
procedure

dnatube
animation

H. Cloning
1.
2.
Clone: an organism that is
genetically identical to
another organism
Examples that occurs in
nature
a. Asexual reproduction in
bacteria & sponges
b. Identical twins are
natural clones
CLONING EXAMPLES
1.
Cloning of transgenic
bacteria creates many
“living factories” used
to make insulin & other
drugs
2. Transgenic sheep
produce milk
containing human
proteins, which may
help with treating
diseases
Bacteria that contain genes
for digesting oil can be
used to clean up oil spills.
(2010 BP oil spill)
SOMATIC CELL NUCLEAR TRANSFER
Dolly: First
cloned animal
Reproductive Cloning
First Cloned Cat
(2001)
I. Genetically Modified Organisms
(GMO)
GM crops have been
modified to produce a
toxin which kills insects –
thus reducing use of
pesticides
 Cows are injected with
hormones made from
recombinant-DNA to
increase milk production

Hunger Games
 Tracker

Jackers
Genetically engineered wasps, coded
to attack anyone or anything that
disturbs their nest. Once they make a
person their target, they follow him
or her far away from their nest.
Tracker-jackers were used as
weapons during the war and planted
around the districts of Panem
J. DNA Fingerprinting
1. DNA fingerprinting: tool used by forensics
scientists to identify a person using DNA.
2. How it Works:
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A sample of the person’s DNA is taken from blood,
semen, bone, or hair.
DNA fragments are placed into a gel & connected to
an electric current
DNA moves through the gel; shortest lengths move
the fastest & longest lengths move the slowest.
A characteristic banding pattern is produced and a
photograph is taken
The banding pattern is unique for each person – thus
called a DNA fingerprint
DNA Fingerprints
Was any of the victims blood
on the defendants clothing?
Which dog was probably
the culprit (dog that bit
the person)?
What are Stem Cells &
Why Do Scientists Want Them?
1.
Stem cells: undefined
cells that reproduce
continuously & can
develop into any type
of cells or tissues
2. The hope is to be able
to produce tissue &
organs for transplants
Stem cell technology
can help those who wait
for organ transplants.
Where do we get Stem Cells?
Embryonic Stem cells are most easily obtained
from embryos and umbilical cords. (work best)
2. Adult Stem cells are found in bone marrow.
1.
What is the Human Genome Project (HGP)?
1. Began in 1999; Completed in 2003
2. Coordinated by National Institutes of
Health (NIH) & U.S. Department of
Energy (DOE)
3. Goals of HGP
a. Identify all genes in the human
genome
b. Determine the sequence of all 3
billion DNA base pairs (Gene
mapping)
c. Store the information into databases
d. Address ethical, legal, & social issues
that arise from human genome
research
Benefits of the Human Genome Project
1.
Find where genes are
located on the chromosomes
and what each is for. (Many
diseased genes have been
found.)
2. Furthered research for fuel
& environmental clean-up
(bacteria genomes)
3. Improved technology for
DNA forensic science
Maps of chromosomes # 13 & #
17; show the location of BRCA 2
& BRCA 1 – breast cancer genes.