1. 13-1
Genetic Engineering

2. Selective Breeding
Humans use the variations in plants, animals, and other organisms to pass down the desirable traits
Examples:
Dogs, livestock (cows, chickens), plants we eat

3. Hybridization
Crossing dissimilar individuals to bring together the best of both organisms
Hybrids are often hardier than either parent
We can get the disease resistance of one plant combined with the food-producing capability of another combined in one plant

4. Inbreeding
Inbreeding is the continued breeding of individuals with similar characteristics
this help maintain desired characteristics in a line of organisms
Because the organisms being breed have similar genes there is a chance to bring together two recessive alleles which can lead to genetic defects

5. Increasing Variation
Selective breeding depends on the variations within each species
Breeders can increase the genetic variation in a population by inducing mutation
Mutations are the ultimate source of genetic variability

6. 13-2
Manipulating DNA
Scientists can use their knowledge of the structure of DNA and its chemical properties to study and change DNA molecules.

7. Genetic Engineering
Genetic Engineering is the process of making changes in the DNA code of a living organism
First the scientists open up the cell and the DNA is separated from the other cell parts

8. Cutting DNA
Scientists can cut the DNA using restriction enzymes, to get smaller pieces
Each restriction enzyme cuts DNA at a specific sequence of nucleotides
The pieces can then be separated by gel electrophoresis

9. Gel Electrophoresis
Pieces of DNA are put into a tray of gel and get separated according to size
An electrical current is run through the gel which causes the DNA pieces to move with the current
The smaller the pieces are the farther they will move away from the starting point

11. Recombinant DNA
Scientists are able to put these pieces of DNA together by using enzymes
It is possible to take a gene from one organism and attach it to the DNA of another organism
DNA made like this is called Recombinant DNA
Scientists make copies of the gene with a technique know as polymerase chain reaction (PCR)

13. 13-3
Transformation
Humans can put a piece of recombinant DNA into a host cell (usually bacteria)
The foreign DNA is joined to a small circular DNA in the bacteria known as a plasmid
the bacteria will produce the human gene/trait
Examples: insulin, growth hormones

15. 13-4
Transgenic organisms
Organisms are called transgenic if they contain genes from other species
Examples:
mice with humanlike immune systems to study effects of diseases on humans
Livestock with extra growth hormones, grow faster and lean (less fat) = better meat

16. Cloning
Scientists are able to take a single cell from an organism and use that cell to produce another organism
This organism will be genetically identical to the original organism