Genetic Engineering Chapter 13
Selective breeding • Allowing animals with certain traits to breed to produce a desired offspring. • Examples:
Luther Burbank (1849-1926) • American botanist who developed the disease resistant Burbank potato • Used process of hybridization : crossing dissimilar organisms to get best of both qualities.
Inbreeding • The controlled breeding of closely related organisms. • Positive effects: controlled traits and characteristics. Pure bred dogs • Negative effects: excessive inbreeding can produce unwanted effects because of lack of variation. Blindness in German shepherds
Increasing variation • Use radiation or chemicals • Can produce new strains of bacteria and new plants.
Polyploidy • Having a multiple of the normal chromosome number. • Example: regular chromosome number is 9. Polyploidy condition could be 18, 27, 36, etc.
DNA manipulation • Cutting DNA • Copying DNA • Changing DNA
DNA Extraction • Where is the DNA located in a cell? • -the nucleus • First must break apart the cell membrane and nucleus to get at the DNA
Cutting DNA • Usually use a restriction enzyme : a chemical used to cut out a specific segment of DNA.
Gel Electrophoresis • Placing a mixture of DNA into a gel and applying an electric current. DNA is then separated according to size.
Reading the DNA • Using a computer, fluorescent dyes, and samples of adenine, guanine, cytosine, and thymine.
Cutting and Pasting • Use DNA synthesizers to make recombinant DNA (DNA from two different organisms spliced together)
Making copies • PCR polymerase. • Used to make multiple copies of a segment of DNA or gene. • Developed by Kary Mullis
Transformation • When a cell (usually a bacterium) takes in DNA from outside the cell. • Example: Griffith’s rats
Plasmids • A small circular molecule of DNA • It often has a DNA sequence that serves as an origin of replication. • Contain genetic markers.
Transgenic organisms • When an organism contains genes from other organisms. • Example: • A tobacco plant that containd DNA from a firefly.
Biotechnology • A “new” field of biology that utilizes genetic engineering to produce new substances in the fields of health and industry.
Transgenic animals • Livestock can grow faster, better quality of meat, resistant to disease. • Cows that produce human proteins in their milk.
Transgenic plants • Usually cash crops such as cotton, corn, wheat, soybeans, etc. • Often incorporates bacterial DNA to make the crop resistant to disease, pests, or chemicals. • Ex: Bt corn
Cloning • Clone: a member of a population of genetically identical cells produced from a single cell. • 1997: first mammal cloned. Dolly, the sheep.
Is cloning a good thing or a bad thing? • Cloning articles
Assignment: • Page 337-338 • 1-10, 13, 16, 17, 22, 23, 32