Genetics       
Chapter 13
Genetic Engineering
Selective Breeding
Allowing only organisms with desired characteristics to breed
Hybridization- crossing dissimilar organisms to bring together the best of both organisms
Hybrid vigor
Selective Breeding
Inbreeding- continued breeding of individuals with similar characteristics
Increased risk of genetic diseases
Increasing Variation
Genetic variation in a population can be increased by inducing mutations
Ex) treat bacteria with radiation
Ex) force plants
 to be polyploids
Genetic Engineering
Making changes in the DNA code of living organisms
DNA Extraction= cells are opened and DNA is seperated
Cutting DNA= use restriction enzymes to cut DNA into small pieces
Separating DNA= gel electrophoresis uses the different size and charge of molecules to separate the DNA
Using the DNA Sequence
Knowing the sequence of an organisms’ DNA allows researchers
to study specific genes,
to compare them with the genes of other organism,
to try to discover the functions of different genes and gene combinations
Reading the DNA Sequence
Cutting and Pasting
Short sequences can be assembled using DNA synthesizers and added to natural DNA using enzymes
DNA from one organism can be added to another with enzymes
Recombinant DNA
Making Copies- polymerase chain reaction (PCR)
Allows us to make many copies of a gene
Cell Transformation
A cell takes in DNA from outside the cell.
In bacteria new DNA is added to plasmids
Genetic marker is added to the new DNA
Cell Transformation- Plants
Use bacteria that insert their plasmids into plant cells
Remove the cell wall and sometimes plants will take up foreign DNA
Directly insert DNA
Transformation is successful when recombinant DNA is integrated into one of the chromosomes of the cell
Cell transformation- Animals
Inject directly into cells (egg cells are large enough)
We can knock out specific genes and replace them
Transgenic Organisms
Organisms that have genes from other organisms
Transgenic Microorganism
Bacteria have the gene for
Human insulin
Human growth hormone
Human clotting factors
Transgenic Animals
Animals are more human like so we can study them
Live stock are more hardy and produce more
Transgenic Plants
Add genes for
Natural insecticides
Resist weed-killing chemicals
Plants that produce human antibodies
Foods that can resist rot
Rice with vitamin A