Today's Question: Homework: Why might scientists want to changethe DNA of a species? • (lab) Genetic Code Kit
Scientists select certain genetic traits of an organism. • By breeding certain species together • By adding genes to an organism • By creating genetically identical organisms • Example- glow in the dark cats! Genetic Engineering-
In bacteria- • Can select a gene to add to the bacteria • Bacteria have a circle of DNA (plasmid) • an enzyme used to break the circle • gene is added at a specific site in the DNA • gene is then expressed by the bacteria The Basics
pGLO in bacteria Example
Must cut DNA with an enzyme ata specific site • Must insert gene and bind it to the active gene in the bacteria • Reassemble DNA How?
Can be used to grow chemicals thathumans use that would otherwise bevery expensive • insulin • HGH (human growth hormone) Why?
Scientists can now do this with plantsand animals as well -make plants that produce their ownpesticides -make cats that glow in the dark Going further
Other method- • There are many ways to select what genes are shown by an organism • Cloning • Selective Breeding • Inbreeding • Hybridization
Cloning Mr. Gnacik’s frog… • Take a cell from Kermit. • Remove its nucleus • Take an egg from Mrs. Hoppy • Remove its nucleus, insert Kermit’s DNA • Implant “fertilized egg” into Mrs. Ribbit • Baby Kermit born! Cloning
Any method of breeding two speciestogether to get desirable traits in theoffspring Selective Breeding-
Inbreeding- • Mating two of the same species together who have desirable traits • thing dogs! • Hybridization- • Mating two different species together to get the best of both species • “Grapple” Selective Breeding-
Good, bad and ugly • Good- • Can increase endangered populations • More efficient ways of farming • new corn- uses 50% less water! • Bad- • Can reduce genetic variety in groups • Many new genes’ effects on humans are unknown • Ugly- • “liger” • should this be done just for the sake of trying?
Can compare your DNA to otherhumans (CSI-style…) Can compare humans to other livingorganisms Other uses-
A method of separating DNA out thathas been cut by enzymes. • Allows researchers to see different sizes of molecules • -DNA is run through a gel with electricalcurrent. • -Gel has holes of different sizes thatslow down larger portions of DNA Gel Electrophoresis-
Today's Question: Homework: Why do so many countries have laws against eating geneticallymodified foods? • (lab) Genetic Code Kit