Transcript Genetic Engineering

Genetic Engineering
Selective Breeding
 What is selective breeding?
 Why do you think humans use selective
breeding?
 What are some examples of selective
breeding?
Selective Breeding
 For thousands of years new varieties of cultivated plants and
domestic animals have resulted from selective
breeding for particular traits.
 Some selective breeding techniques include artificial
selection, where individuals with desirable traits are mated
to produce offspring with those traits.
Selective Breeding
 Selective breeding is a process by which only individuals with
desired traits are allowed to produce the next generation.
 Artificial selection is human intervention in animal or plant
reproduction to produce desirable traits in the next
generation.
Inbreeding
 The continued breeding of individuals with similar characteristics,
usually from the same family.
 Inbreeding is used often in pedigreed dogs to ensure the
characteristics that make breeds unique are well-preserved.
Hybridization
 Crossing individuals with desired characteristics to produce
offspring with a combination of both traits.
 Example:
 Santa Gertrudis cattle
An Example of Selective Breeding
 Brahman Cattle
 English Shorthorn Cattle
 Good resistance to heat,
 Good beef, but poor
but poor beef.
resistance to heat.
An Example of Selective Breeding
 Santa Gertrudis Cattle
 Good heat resistance AND good beef.
 http://www.youtube.com/watch?v=QDTFrD-9J-o
Applications of Genetic Engineering
 Transgenic organisms
 Organisms that contain the genes of other organisms
 A gene from one organism is inserted into the cells of another
organism.
 The transformed cells are then used to grow new organisms.
Transgenic Microorganisms
 Bacteria transformed with the genes for human proteins can
now produce compounds such as:
 Insulin
 Human Growth Hormone
 Clotting Factors
Transgenic Animals
 Mice have been produced with human genes that make their
immune systems similar to that of humans in order to study
the effects of diseases on the human immune system.
 Attempts are being made to produce chickens that are
resistant to bacterial infections that can cause food poisoning.
 Livestock have extra copies of growth hormone to grow
faster and produce leaner meat.
Transgenic Plants
 Plants are bred with genes that come either from a similar
plant, or a completely different species such as bacterium.
 Monsanto
 Are GM crops safe?
Cloning
 http://www.youtube.com/watch?v=YoEWYJHf0kU