1. Chapter 9 Biotechnology

2. DNA Extraction Why would we want to extract DNA?
Use chemicals to break down cell membrane/wall and nucleus.
The DNA is now free to be extracted
DNA is sticky, and can be easily pulled out of a mixture.
This is called “spooling” DNA

3. “Spooled” DNA
Extracted
DNA

4. Restriction Enzymes
After DNA has been extracted, restriction enzymes are added
Cut DNA at VERY SPECIFIC sites
Specific nucleotide sequence
Makes large DNA molecules more manageable and easier to study.
Cuts it up into smaller sections.

5. Restriction enzymes

6. Gel electrophoresis
An electrical current is used to separate a mixture of DNA fragments from each other.
Fragments are sorted by size.
The smaller the fragment, the further it moves.
DNA moves towards positive end of gel.
DNA is negatively charged because of the phosphate
Positive and negative attract.

7. Gel Electrophoresis

8. DNA fingerprinting
There is a 1 in 5.4million chance that someone could have the same DNA as you.
What are some of the ways that we use DNA fingerprinting today?

9. Cloning
A clone is a genetically identical copy of a gene or an organism
Asexual Reproduction = 100% identical
Example: Plants clone themselves
Example: Bacteria and binary fission = split into 2
Example: Sea star re-growing lost limbs (regeneration)

10. Cloning A body cell is taken from a donor who is going to be cloned.
An unfertilized egg is taken from another individual and the nucleus is removed.
The nucleus of the body cell is fused with the unnucleated egg cell to create an embryo.
The embryo is then stimulated to begin dividing.
Embryo is implanted into a surrogate mother.
Cloning “Dolly” 1997

11. Positive and negative of cloning.
Cloning raises concerns.
low success rate
clones “imperfect” and less healthy than original animal
decreased biodiversity
organs for transplant into humans
save endangered species
Higher crop yields

12. Why aren't the cloned cats exactly identical?
Environment has an affect on gene expression
Why?

13. Transgenic/Recombinant DNA
Plasmid – tiny rings of DNA found in bacteria
A transgenic organism is one that has one or more genes from another organism inserted into its genome.
Genetically modified organism (GMO)

14. Transgenic organisms: Genetically engineered crops
Resistant to frost, disease and insects
Smaller amount of pesticides needed to protect plant
More and bigger plants produced

15. Human Genome Project Started in 1990
Research effort to sequence all of human DNA
46 chromosomes
Over 3.3 billion nucleotides
Mapping every gene location (loci)
Conducted by scientists around the world

16. Gene Therapy
The replacement of a defective or missing gene, or the replacement of a new gene, into a person’s genome to treat a disease.
First successful gene therapy took place in 1990
Much of gene therapy is still experimental
Researchers are studying many different methods to treat cancer
Gene to stimulate persons immune system to attack cancer cells
Insert “suicide” gene into cancer cells.