3 Description: Selective Breeding: The oldest and most obvious way of improving species Select a few individuals to serve as parents for the next generation Cross individuals with a desired traitExample(s): Luther Burbank produced 250 new varieties of fruit in addition to the daisy and Burbank Potato
4 Description: Inbreeding: Technique used to maintain a stock of similar organismsIndividuals with similar characteristics are crossed so the traits will appear again in next generationPROBLEM: Increased risk of recessive genetic defects.Example(s): Purebred dogs
5 Description: Hybridization: A cross between dissimilar individuals of different, but related speciesOffspring are often hardier than either parentExample(s): Commercially grown corn
6 Description: Mutagens: A breeder might not want to wait for a beneficial mutation to appear naturally. They catalyze this!Mutagens include radiation and chemicals. They cause mutationsWith luck and time, breeders end up with “good” mutantsExample(s): Useful bacterial strains. Some bacteria can digest oil are are useful in cleaning up oil spills.
7 GENETIC ENGINEERINGARTIFICIALLY ALTERING GENETIC MAKE-UP, OFTEN USING DNA FROM ONE ORGANISM IN ANOTHER
8 Restriction Enzymes: STEP 1: ISOLATE THE DESIRED GENE Proteins that cut DNA sequences at specific regionsMore than 75 are knownEach one recognizes a specific site of 4-6 nucleotide pairs and cutsMake it possible to cut DNA into fragment that can be isolated, separated and analyzed
9 STEP 2: COMBINE THE GENE(S) WITH DNA FROM RECIPIENT ORGANISM DNA Recombination:Insert desired gene into organism--often bacterial plasmid (small circular pieces of bacterial DNA)DNA now consists of parts from different kinds of organismsThis is “recombinant DNA”
10 DNA Insertion: STEP 3: INSERT COMBINED DNA INTO NEW ORGANISM It is easiest to transfer DNA into bacterial cellsMix plasmids in with millions of bacteria in a salt solutionAltered plasmids will carry foreign DNA into bacterial cellsBacteria are isolated and grown into large colonies to magnify the amount of the gene (DNA cloning)Using different techniques, recombinant DNA can be inserted into yeast cells, animals and plants
11 DETERMINING THE NUCLEOTIDES ON DNA, USING GEL ELECROPHORESIS GENETIC SCREENINGDETERMINING THE NUCLEOTIDES ON DNA, USING GEL ELECROPHORESIS
12 DNA Sequencing: READ NEW SEQUENCES OF DNA Only one strand is used in DNA sequencingMany copies of the strand are needed and produced via DNA cloningAdd radioactive phosphorus to DNADivide DNA into 4 groups that undergo different chemical treatments that break DNA into piecesDNA pieces are separated by gel electrophoresis and banding patterns are analyzed to reveal sequence of bases
13 ORGANISMS THAT CONTAIN FOREIGN GENES TRANSGENIC ORGANISMSORGANISMS THAT CONTAIN FOREIGN GENES
14 Description: BACTERIA: Organisms that contain foreign genes are transgenicWhen a gene coding for a human protein is inserted into bacteria, the recombinant cells may produce large amounts of the proteinExample(s): Human growth hormone, Insulin to treat diabetes, Interferon to block growth of viruses and treat cancer
15 PLANTS:Description:DNA can be injected into plant cells directly or attached to plasmids of certain species of bacteria that infect plant cellsExample(s):The goal is to produce plants that manufacture natural insecticides and fertilizerFirefly gene inserted into tobacco plant and it glowed!
16 Description: ANIMALS: DNA can be introduced into reproductive cells by injection, among other techniquesExample(s):Scientists introduced growth hormone gene from rainbow trout into carp. The new fish were bigger and faster growing.Another goal is to produce farm animals that are resistant to disease.
17 The production of genetically identical organisms from single cells CLONINGThe production of genetically identical organisms from single cells
18 Description: CLONED ANIMALS: The nucleus of an egg cell is removed and replaced with a nucleus taken from an adult organismThe egg is grown inside a foster motherThe newborn is a genetic copy of the adult from which the nucleus was takenExample(s):In 1997 “Dolly” the sheep was cloned. Cows and mice have been cloned as well.
19 Genetic Engineering to treat disease GENE THERAPY:Transgenic HumansGenetic Engineering to treat disease
20 Are you FOR or AGAINST GENETIC ENGINEERING? GENETIC ENGINEERING IN HUMANS:Description:Transgenic humans can be produced by inserting foreign genes into human cellsRemove cells from an individual and grow them in culture. Transform with a corrective gene and reinsertViruses can be modified so they cannot cause diseaseNow that you have some scientific background you can make and support your arguments.Are you FOR or AGAINST GENETIC ENGINEERING?Example(s):Cystic fibrosis, Tay-Sachs disease and sickle-cell anemia are examples of genetic disorders that could be treated in this manner
21 Legislative Analyst - presents the necessary scientific background required to understand the genetic engineering application and the proposition – the law that is being proposed. Paper and presentation should include:Description of propositionExplanation of SCIENCE background relevant to propositionProponent - presents the argument in favor of the proposition and the science supporting the proposition.Paper and presentation should include:Position (YES on proposition)Explanation of SCIENCE in support of propositionRelevant ethical issues related to propositionOpponent - presents the rebuttal to the argument in favor of the proposition and the science against the proposition.Position (NO on proposition)Explanation of SCIENCE against of proposition