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• Selective Breeding
• Recombinant DNA
Genetic Engineering
– Transgenic Organisms
• Genetic Engineering
• Ethics
Biology
SPI 3210.4.9, SPI 3210.T/E.2
Selective Breeding
Inbreeding
• The most direct method of producing a desired offspring
• Choosing the best of the best (characteristics) and breeding the two organisms together to achieve the desired results‐ perfection
– Purebred
• Problems/Risks: Problems/Risks
– deformities in the joints – progressive blindness in German shepherds and golden retrievers
– Inbreeding
– Hybridization
• Examples: breeding corn snakes, dogs, pigs, corn, flowers, potatoes, horses, etc.
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Hybridization
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Selective Breeding vs. Genetic Engineering
• A cross between different (but related) species
• Usually hardier or more fit than the parents
• What kind of characteristics have food crops been selectively bred? • What are some examples of harmful effects of selective breeding?
of selective breeding?
• When a breeder doesn’t want to wait for the trait to appear naturally they can force a change through mutagenesis
– Aka hybrid vigor
Aka hybrid vigor
• Corn
– disease resistance – yield per acre – nutritional value
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Transgenics: Manipulating Genetics
Mutagen
• Agent or substance that uses chemicals or radiation to force a change or mutation
– Some harmful
– Some beneficial
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(Discovery Education, 2002)
Mutagenesis
GMO’s
The process of using mutagens to increase the mutation rate for a desired result • Vehicle: Bacteria
• Genetically Modified Organism
– Any organism that has acquired one or more genes by artificial means
• Transgenic if the source of the new genetic if the source of the new genetic
material is from a different species
– SSmall size and fast reproduction rate make ll i
df t
d ti
t
k
bacteria the preferred method
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Photo: http://www.microbeworld.org/htm/aboutmicro/microbes/types/bacteria.htm
Classical vs. Transgenic Breeding
• Plants http://www.teachers
domain.org/9‐
12/sci/life/gen/br
eeding/index.html
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GE Techniques
• Animals http://www.srtp.org.uk/engenpre.shtml
• Stem Cell Research http://stemcells.nih.gov/index.asp
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1.
2.
3.
4.
Genes are cut by restriction enzymes DNA Recombination
DNA Insertion
DNA Sequencing
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GE Techniques
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Cut and Paste DNA
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Restriction Enzyme: Source and Site of Action
http://www.people.virginia.edu/~rjh9u/restrenz.html
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PCR Technique
Polymerase Chain Reaction (PCR) produces
billions of copies of a select segment of DNA
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Step 1
Just for fun: PCR song
1. Heat is added to separate strands
2. The mixture is cooled and primers bind to strands
3. DNA polymerase adds nucleotides to strands, producing two daughter molecules
4. The procedure is repeated, starting at Step 1.
Step 2
Step 3
Step 4
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Gel
• To compare the DNA from two different individuals a relatively large number of DNA copies are required. • Polymerase chain reaction (PCR) enables scientists to rapidly generate billions of copies of a particular DNA sequence from a very small sample for chemical analysis. • This technique is widely used in basic genetic research
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–
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diagnosing genetic disorders
studying evolutionary relationships
criminal investigations
pharmaceuticals
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DNA Fingerprinting
• No human is exactly alike
• Tool used in criminal investigations
Applications Links to research:
http://www.biology.washington.edu/fingerprint/howis.html
http://www.dnalc.org/resources/aboutdnafingerprinting.html
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DNA Fingerprint
Forensic DNA Analysis
• http://www.teachersdomain.org/9‐
12/sci/life/gen/sheppard/index.html
• http://www.pbs.org/wgbh/nova/sheppard/an
h //
b
/ bh/
/h
d/
alyze.html
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Ethical Impacts of Biotechnology
• Should genetic modifications to humans and other organisms be closely regulated? • If future technology allows it, do you think If future technology allows it do you think
parents should be able to choose specific characteristics for their babies? • Do the benefits of new genetic tools outweigh the risks? List pros and cons. (Teacher’s Domain, 2003) 27
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Medical Advances
Ethics
1. Finding cures for illness
2. Development of new drugs
3. Stem cell research
Finding Cures • DNA Databases:
4:14 min http://www.pbs.org/wgbh/nova/programs/ht/qt/2809_qlg_13.html
• Genetic Modification 4:27 min
http://www.pbs.org/wgbh/nova/programs/ht/qt/2809
p //
p
g/ g /
/p g
/ /q /
_q
qlgg_15.html
• GM Fish
Harvest of Fear http://www.pbs.org/wgbh/harvest/
5:32 min
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Designer Babies
Cloning
http://www.cbsnews.com/video/watch/?id=6078982n
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GM Animals
Diagram of plant cloning through tissue culture propagation
TransgenicManipulation
activity
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(Freudenrich, 2001)
(Levine & Miller, 2012)
GM Animals
• Scientists in Canada combined spider genes into the cells of lactating goats. The goats began to produce silk along with their milk.
• The silk can be extracted from the milk and woven into a thread that can be used to create a light, tough, and flexible material.
(Levine & Miller, 2012)
(Levine & Miller, 2012)
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Genetically Modified Crops
on the Market
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•
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Corn
Soybeans
Cotton
Canola
Sugar beets
Alfalfa
Hawaiian Papaya Yellow “crook neck” and zucchini squash
• There are currently no genetically modified varieties of barley, edible beans, flax, oats, peas, rice, spelt, sunflowers, and wheat being grown. (Roseboro, 2011)
Adoption of Genetically Engineered Crops in the U.S.
• This data product summarizes the adoption of herbicide‐tolerant and insect‐resistant crops since their introduction in 1996.
• The
The tables below for corn, cotton, and soybeans, tables below for corn, cotton, and soybeans,
provide the data obtained by USDA's National Agricultural Statistics Service (NASS) in the June Agricultural Survey annually for 2000 through 2011. Genetically engineered varieties of corn, upland cotton, and soybeans, by State and for the United States, 2000‐11
• Many people are interested in information about the global GE acreage. USDA does not collect these data. Estimates are produced by the International Service for the Acquisition of Agri‐biotech Applications (ISAAA) and can b f
be found in the report, Global Status of d i th
t Gl b l St t
f
Commercialized Transgenic Crops: 2011.
• See more on recent trends in GE adoption, and documentation to the data.
(USDA, 2012)
Are you eating GM foods?
• It’s estimated that 60% of the US food products contain GE ingredients • http://www.geo‐pie.cornell.edu//crops/ingredients.html
(USDA, 2012)
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Resources
Problems/Concerns
• Techniques of genetic modification allow scientists to change an organism's genetic code
– creating a plant or animal that never before existed
– Not surprisingly, this idea frightens many people Discovery Education. (2002). Transgenics: Manipulating Genetics. [Video Segment]. Available from http://www.discoveryeducation.com/ Freudenrich, C. (2001). How Cloning Works. Retrieved January 23, 2011 from website http://science.howstuffworks.com/environmental/life/genetic/cloning.htm.
Levine, J., Miller, K. (2012). Biology. New Jersey: Pearson Education, Inc.
• They fear innumerable unforeseen possibilities, including creatures or diseases against which we have no defense. • Many scientists strongly acknowledge these fears, saying that despite all we know about genetics, there is still much that remains shrouded in mystery.
Mackean, D. (2009). IGCSE Biology, 2nd ed. London, UK: Hodder Education.
Nowicki, S. (2012). Holt McDougal Biology. Orlando: Houghton Mifflin Harcourt Publishing Company.
Roseboro, K. (2011). The Non‐GMO Sourcebook. Retrieved June 27, 2012 from website http://nongmosourcebook.com/geneticallymodifiedcropsmarket.php.
United States Department of Agriculture. (2012). Adoption of Genetically Engineered Crops in the U.S. Retrieved June 27, 2012 from website http://www.ers.usda.gov/data‐products/adoption‐
of‐genetically‐engineered‐crops‐in‐the‐us/recent‐trends‐in‐ge‐adoption.aspx. 43
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