Biology Unit 5 Notes: Genetic Engineering

(1) What Is Genetic Engineering? Genetic Engineering = Altering the genetic code of an organism. How is this most commonly used? Selective Breeding of Plants + Animals Types: Selective Breeding Gene Therapy Cell Transformation Cloning

(2) Selective Breeding Takes advantage of naturally occurring genetic variation in plants, animals, and other organisms. Used to control which desired traits pass on to the next generation.

(3) Gene Therapy An absent or faulty gene is replaced with a normal, working gene. Viruses are often used because they have the ability to enter a cell’s DNA. How Does This Work? The virus is modified so that it cannot cause disease. A DNA fragment with the replacement gene is spliced to the viral DNA. The patient is infected with the modified viruses Unfortunately, these experiments have not been very successful. Gene therapy remains a high-risk, experimental procedure.

(4) Cell Transformation Cell Transformation = Genetically Modified A cell takes in DNA from outside the cell. Can use it to insert desired genes/traits. When organisms contains genes from another species, they are called transgenic organisms.

Transgenic Organism Examples Mice  Used to study how the altering of human-related genes impacts the organism. Cattle  Alter the fat / muscle composition of the animal. Plants  Can become naturally resistant to insects and viruses, or contain vitamins. Bacteria  Can produce large quantities, quickly, of medicines like insulin and growth hormones.

(5) Cloning Clone  A member of a population of genetically identical cells produced from a single cell. Researchers hope that cloning will enable them to make copies of transgenic animals to help save endangered species.

Normal Sheep cells