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Learn about selective breeding and how humans manipulate DNA to produce specific products using biotechnology and recombinant DNA technology. Discover the use of bacteria as vectors, genetic engineering in bacteria, and the creation of genetically modified organisms (GMOs) in plants and animals. Explore the GMO controversy, DNA technologies like the Human Genome Project, PCR, gel electrophoresis, and the ethics of genetic ownership.
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Selective Breeding Humans have been breeding animals to manipulate their DNA/Traits for many years! Selective Breeding – humans only allow animals with desired characteristics to breed and produce offspring Example – dogs bred to be “better hunters”, “better retrievers”
Biologists Manipulate DNA • Scientists use biotechnology to perform practical tasks & produce specific products (medicines, etc.) • Today, we manipulate the genomes (DNA/Genes) of organisms like plants and animals. • Biotechnology – the process of manipulating organisms, cells, or molecules to produce specific products.
Recombinant DNA Technology Technology where DNA and/or genes from different sources are combined to change the genetic composition of living organisms…even genes from different species! Recombinant DNA – DNA (made in a lab) that is then attached to the DNA of another organism (thus changing a specific characteristic of that organism) FYI - A Few Uses of DNA technology: • Make more “nutritious” crops (ex. Golden Rice) • Make medicine in large quantities (ex. Goats)
Bacteria – Common “Vector” Bacteria are commonly worked with in biotechnology because they can acquire new genes in many ways and copy DNA in large quantities! 3 Ways Bacteria can Acquire DNA: • Conjugation - “Tunnel” forms a bridge between the bacteria where DNA can travel. 2. Transformation – bacteria can “take up” free floating DNA into their own DNA 3. Use Plasmids
Engineering Bacteria • Bacteria contain plasmids • Plasmids are small circular pieces of DNA separate from the bacterial chromosome. • Carry cool genes (for awesome traits!)
Plasmids Bacteria can transfer/swap plasmids to one another and scientists can manipulate plasmids to make them useful to us!! Example: • Insert a gene (to make a medicine) into a plasmid • Put the plasmid into bacteria • When the bacteria reproduce they make many copies of the gene & the medicine!
Desired Gene • Cut • Use restriction enzymes to cut the desired DNA/gene out of a larger chromosome • Paste • Put the desired DNA/gene fragment into a plasmid • Insert - Put the plasmid into a bacterium • Bacteria reproduce - making many copies of the desired gene!!
Useful Products Using Genetic Engineering • Bacteria make chemicals that clean up hazardous spills • Plants that are more nutritious (“golden rice”) • Cattle that can make insulin hormone in their milk for people with diabetes • Goats make antibiotic to secrete in their milk
13.3 Genetically Modified Organisms • A genetically modified organism (GMO) is any organism that has acquired any genes artificially. • If a species is called TRANSGENIC if it has foreign genetic material from a different species in it.
Just a few…GMO FOODS • Honey • Cotton • Tomatoes • Corn • Vegetable Oil • Peas • Potatoes • Many cereals
Genetically ModifiedPlants • Over 88% of soybean and 94% of corn crops are genetically modified ! • Most common (GMO) genetic modifications: • Genes for disease resistance • Genes to resist insect and fungal pests
Genetically Modified Animals • Goals for GMO animals… • Produce mass quantities of medications (ex. insulin) • Get animals to market quicker (salmon) • Breed animals with better quality products (sheep wool) • FUN!! $$$$$$$ Fincasters Episode 8 GloFish - YouTube
Few more examples… Genetically Modified Salmon - Coming Soon? - YouTube • Transgenic Cows
The GMO Controversy Although studies to date have shown that eating genetically modified foods have no negative health affects…people continue to demand stricter regulations. Major Concern: GMO food can pose unknown health risk…people are requesting strict labeling laws! **”ORGANIC CRAZE”**
DNA Technologies & Their Uses • Human Genome Project • PCR – Polymerase Chain Reaction • Gel Electrophoresis • Gene Therapy • Cloning
DNA Technologies Human Genome Project (HGP) An international scientific research project with the goal of determining the sequence of chemical base pairs which make up human DNA, and of identifying and mapping all of the genes of the human genome from both a physical and functional standpoint. Started in 1990 Completed in 2003 Ethics - Genetic Ownership of Genes
DNA Technologies FYI: Sometimes it is necessary to make many copies of a piece of DNA from a single sample. • PCR or Polymerase Chain Reaction technique used to mass produce specific sequences of DNA Thermocycler
Gel Electrophoresis!!! • Technique used to separate and analyze fragments of DNA. • Produces “banding patterns” based on the size of the DNA fragments as they move through a gel due to electric current.
How it works! DNA is cut into “fragments” by restriction enzymes Smaller DNA fragments move further DNA “fragments” move through gel using electric current
Online Gel Electrophoresis Gel Electrophoresis Virtual Lab
DNA Fingerprint • Just like every person has their own unique fingerprint…everyone has a unique banding pattern produced by their restriction fragments in gel electrophoresis. • 97% of our DNA is “junk” or non-coding and is extremely different from any other persons “junk” DNA. • Forensics!!
Who committed the crime? Suspect # 1 2 3 4 5 6 7 Bloodstain evidence from crime scene of guilty person!
Gene Therapy! • Used to identify a “bad/faulty” gene ( that makes someone “sick”) …..and REPLACE it with a “good” gene. • Occurs in “embryo” development! • Uses viruses to carry the DNA into and out of the body.
Cloning Uses a single cell from an adult organism to grow an identical new individual. “Dolly” 1997
Stem Cells and Homeotic Genes • Stem cells – cells (early in development) that remain undifferentiated and have the potential to be any type of cell. • Homeotic Genes – genes that control development of specific locations in organisms.
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