2 DNA Extraction Why would we want to extract DNA? Use chemicals to break down cell membrane/wall and nucleus.The DNA is now free to be extractedDNA is sticky, and can be easily pulled out of a mixture.This is called “spooling” DNA
4 Restriction EnzymesAfter DNA has been extracted, restriction enzymes are addedCut DNA at VERY SPECIFIC sitesSpecific nucleotide sequenceMakes large DNA molecules more manageable and easier to study.Cuts it up into smaller sections.
6 Gel electrophoresisAn electrical current is used to separate a mixture of DNA fragments from each other.Fragments are sorted by size.The smaller the fragment, the further it moves.DNA moves towards positive end of gel.DNA is negatively charged because of the phosphatePositive and negative attract.
8 DNA fingerprintingThere is a 1 in 5.4million chance that someone could have the same DNA as you.What are some of the ways that we use DNA fingerprinting today?
9 CloningA clone is a genetically identical copy of a gene or an organismAsexual Reproduction = 100% identicalExample: Plants clone themselvesExample: Bacteria and binary fission = split into 2Example: Sea star re-growing lost limbs (regeneration)
10 Cloning A body cell is taken from a donor who is going to be cloned. An unfertilized egg is taken from another individual and the nucleus is removed.The nucleus of the body cell is fused with the unnucleated egg cell to create an embryo.The embryo is then stimulated to begin dividing.Embryo is implanted into a surrogate mother.Cloning “Dolly” 1997
11 Positive and negative of cloning. Cloning raises concerns.low success rateclones “imperfect” and less healthy than original animaldecreased biodiversityorgans for transplant into humanssave endangered speciesHigher crop yields
12 Why aren't the cloned cats exactly identical? Environment has an affect on gene expressionWhy?
13 Transgenic/Recombinant DNA Plasmid – tiny rings of DNA found in bacteriaA transgenic organism is one that has one or more genes from another organism inserted into its genome.Genetically modified organism (GMO)
14 Transgenic organisms: Genetically engineered crops Resistant to frost, disease and insectsSmaller amount of pesticides needed to protect plantMore and bigger plants produced
15 Human Genome Project Started in 1990 Research effort to sequence all of human DNA46 chromosomesOver 3.3 billion nucleotidesMapping every gene location (loci)Conducted by scientists around the world
16 Gene TherapyThe replacement of a defective or missing gene, or the replacement of a new gene, into a person’s genome to treat a disease.First successful gene therapy took place in 1990Much of gene therapy is still experimentalResearchers are studying many different methods to treat cancerGene to stimulate persons immune system to attack cancer cellsInsert “suicide” gene into cancer cells.