Presentation on theme: "Genetic Engineering Genetic Engineering is the process of making changes in the DNA code of living organisms. Genetic Engineering and DNA Technology can."— Presentation transcript:
Genetic Engineering Genetic Engineering is the process of making changes in the DNA code of living organisms. Genetic Engineering and DNA Technology can be used to –Cure diseases –Treat genetic disorders –Improve food crops –Produce vaccines and other useful drugs
Genetic Engineering Includes Selective Breeding & Crossbreeding Recombinant DNA Transgenic Organisms PCR DNA Fingerprinting Gel Electrophoresis 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.
Hybridization (Crossbreeding) Producing new organisms by the mating individuals of different breeds, varieties, or species Male Donkey + Female Horse = Mule
Recombinant DNA rDNA has been artificially created –DNA from two or more sources is recombined into a single molecule To create rDNA, scientists use restriction enzymes to cut DNA in precise locations Restriction enzymes create “sticky ends” that allow the DNA to bind to another piece of DNA with the same sticky ends
Recombinant Bacteria 1.Remove a Plasmid –A plasmid is a small circular piece of DNA found in bacteria 2.Cut the Bacterial DNA with restriction enzymes 3.Cut the desired gene from another organism’s DNA with restriction enzymes 4.Combine the cut pieces of DNA together and insert them into bacteria. 5.Reproduce the recombinant bacteria. 6.The foreign genes will be expressed in the bacteria.
Benefits of Recombinant Bacteria 1.Bacteria can make human insulin or human growth hormone. 1.Bacteria can be engineered to “eat” oil spills.
Transgenic Organisms The genetic code is universal, therefore it is possible to make organisms that are transgenic Transgenic organisms contain genes from other species They are also called GMO’s – Genetically Modified Organisms This tobacco plant glows in the dark because scientists gave it the gene that causes fireflies to glow
Transgenic Plants Disease-resistant and insect-resistant crops Hardier fruit 70-75% of food in supermarket is genetically modified.
Transgenic Animals Mice – used to study human immune system Chickens – more resistant to infections Cows – increase milk supply and leaner meat Goats, sheep and pigs – produce human proteins in their milk
Polymerase Chain Reaction PCR PCR is a fast and inexpensive technique used to amplify (copy) small amounts of DNA 1.Heat the DNA so it “unzips”. 2. Add the complementary nitrogenous bases. 3. Allow DNA to cool so the complementary strands can “zip” together.
DNA Fingerprinting A technique used by scientists to distinguish between individuals of the same species using only samples of their DNA Unless they are identical twins, individual organisms all have unique DNA. The chemical structure of the DNA may be the same (A, T, C & G), but the order of the base pairs is different
DNA Fingerprinting Process First, DNA must be obained from blood, bodily fluids, hair roots, skin, or elsewhere After the DNA is isolated, it is amplified using PCR Then the DNA is treated with restriction enzymes –Cut the DNA at specific sequences This results in different sized fragments These fragments are separated, based on size, using a process called Gel Electrophoresis
Gel Electrophoresis DNA fragments are separated as they migrate through an agarose gel matrix This size-based separation occurs when an electric current is applied to the gel
Gel Electrophoresis DNA is a negatively charged molecule, so it will move toward the positive end of the chamber The smaller fragments will move faster and farther than the larger fragments
Gel Electrophoresis Steps 1. “Cut” DNA sample with restriction enzymes. 2. Run the DNA fragments through a gel. 3. Bands will form in the gel. 4. Everyone’s DNA bands are unique and can be used to identify a person.