ch. 13.3: genetically engineered organisms objectives: 1.describe how biologists genetically modify...
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Ch. 13.3: Genetically Engineered Organisms
Objectives:
1. Describe how biologists genetically modify plants and animals.
2. Explain a technique used to clone animals.
3. Summarize the GMO controversy
Vocabulary G.M.O. Transgenic
Selective Breeding: Old School Genetic Engineering indirect manipulation of DNA select parents with desirable traits create “better” individual oldest way to improve a species breed cats, dogs, horses, trees, mice
Selective Breeding: Methods1. Inbreeding
- to maintain traits in a population- mate parents with similar genomes- keeps desirable traits, but increases risks for undesirable mutations (illness/disease)
2. Outbreeding (Hybridization)- Crossing of distantly related organisms- offspring sterile but hardier (hybrid vigor)- ex. Mule, hybrid corn, ligers, etc.
Genetic Engineering
Direct manipulation of DNA- cutting and pasting of genes- design organisms or create transgenic organisms
Creates a transgenic organism- organism with foreign DNA or rDNA
Genetically Modified Organism = GMOAny organism that has acquired genes by artifical means.
Genetic Engineering: Basic Steps
1. Isolate desired DNA sequence Restriction enzymes cut and remove DNA sequences.
2. Attach desired DNA to a VECTORLigase binds DNA fr. different sources.
Vector = bacteria plasmid or virus that will carry recombinant DNA to host.
3. Cloning: Host organisms transcribes and translates desired DNA sequence. Makes MANY COPIES of enzyme or protein.
Creating Plant GMOs Applications
Insert genes for:
natural insecticides
Pesticides
Growing larger fruits/bigger flowers
Increase “nutrient” content.
Common in soybeans, rice, corn, wheat
Creating Animial GMOs
Applications
Bigger cattle, leaner meat
More milk production
Better wool production
Have animals produce human proteins to treat disorders.
Animal ClonesSteps
1. Remove nucleus fr. Egg.
2. Replace nucleus w/ nucleus (and chromosomes) fr. a somatic cell
3. Shock w/ electricity to stimulate cell division
4. Place embryo in surrogate female for gestation.
Sheep, cattle, dogs, cats, pigs, etc.
Problems: advanced aging and cancer in clones.
GMO Controversy
Pros: New genes can improve crops or animals.
Cons: Could GMOs be harmful to us?
New allergies? Cancer/illness?Not many studies. Not regulated.Economic concerns
Cloning & Stem Cell Controversy
Stem cells = undifferentiated cells that can turn into any type of cell (nervous, cardiac, skin, etc.)
Could be used to treat a host of illness/disease
Repair damaged spinal cord tissue
Replace damaged cardiac muscle
Sources: Embryos; Adult cells: bone marrow and cord blood (Embryos have the most promise/potential)
Therapeutic Cloning
Use embryonic stem cells to create specialized human cells.
Goal: Cure disease
Embryo does not develop into a human.
Allowed in U.S. (state by state) w/ restrictions
Reproductive Cloning
Create a human clone.
Strictly prohibited!