I.Manipulating DNA A.Molecular biology tools – Used to make changes in the DNA code of a living organism 1.Extraction – DNA can be extracted using simple chemicals that open the cell and separate the DNA. 2.Cutting DNA – Large DNA molecules are cut into smaller segments by restriction enzymes. 4
A restriction enzyme will cut a DNA sequence only if it matches the sequence precisely. Recognition sequences DNA sequence Restriction enzyme EcoR I cuts the DNA into fragments Sticky end 5
3.Separating DNA - gel electrophoresis uses a porous gel to separate DNA segments by electric charge. 6
DNA plus restriction enzyme Mixture of DNA fragments Gel Power source Gel Electrophoresis Longer fragments Shorter fragments 7
B. Using the DNA sequence – researchers can study specific genes and to try to discover the functions of different genes and gene combinations. 8
II.Cell Transformation A.Transforming bacteria - foreign DNA is first joined to a small, circular DNA molecule known as a plasmid 1.Plasmids are found naturally in some bacteria. 2.Plasmids – have a genetic marker (special gene) so a researcher can tell bacteria that carry the plasmid (and the foreign DNA) from those that don't. 9
Recombinant DNA Gene for human growth hormone Human Cell Bacteria cell Bacterial chromosome Plasmid Sticky ends DNA recombination Bacteria cell containing gene for human growth hormone DNA insertion 10
III.Applications of Genetic Engineering A. Transgenic Organisms - contains genes from other species. 1.Transgenic Microorganisms - Transgenic bacteria have been used to produce: insulin Human growth hormone clotting factor 2.These can be produced because the human genes can be spliced into the bacterial plasmid. 12
Insulin-dependent diabetes can now be treated with insulin produced through the use of 1.transgenic plants. 2.transgenic animals. 3.transgenic microorganisms. 4.transgenic fungi.
Transgenic tobacco plants that glow in the dark were produced by transferring the gene for luciferase from a 1.clone. 2.bacterium. 3.firefly. 4.jellyfish.
The first mammal to be cloned was a 1.sheep. 2.horse. 3.dog. 4.cat.
In producing a cloned animal, an egg cell is taken from a female and its nucleus is removed. A body cell is taken from a male. The clone from this experiment will 1.look just like the female. 2.be genetically identical to the male. 3.have a mixture of characteristics from both animals. 4.resemble neither the male nor the female.
Animals produced by cloning have been shown to 1.all be perfectly healthy. 2.suffer from a number of health problems. 3.live longer than uncloned animals. 4.be less intelligent than uncloned animals.