1. Genetics 3.5

2. Gel Electrophoresis
Gel electrophoresis is used to separate proteins or fragments of DNA according to size.
Enzymes are used to break up long filaments of DNA into varying sizes of fragments.
DNA is placed into small wells in the gel
The gel is exposed to an electric current positive on one end negative on the other.

3. Gel Electrophoresis
Results are that the biggest, heaviest, and least charged particles do not move through the gel and get stuck close to the wells.
The smallest and most charged particles pass through the gel to the other side
Intermediate particles are distributed in-between.
The DNA will have a banded pattern

4. Gel Electrophoresis Last Step – gel is treated with a gel-stain
Stain makes DNA fragments visible under U.V. Light
DNA show up as bands in the gel
Each band represents one particular DNA size.

5. Polymerase Chain Reaction (PCP)
A technique that makes many copies (amplifies) of a certain segment of DNA without using living cells
Can produce billion identical copies of the first original DNA molecule in a couple of hours
This technique can copy one specific segment from within a tremendous length of DNA
Can be used to copy clone 5,000 year old DNA from human remains
In medicine – PCR can be used to detect viral genes in cells
Thermocycler

7. DNA Profiling
The process of matching an unknown sample of DNA with a known sample to see if they correspond
AKA DNA fingerprinting
Like regular fingerprinting
Each individual has their own banding pattern produced by restriction fragments
Unless you are an identical twin

8. Applications of DNA Profiling
Used in paternity suits
At a crime scene, forensics specialist can collect samples such as blood or semen which contain DNA
DNA is compared via gel electrophoresis is used to compare the collected DNA with suspects.

9. Applications of DNA Profiling
Can be used to clarify relationships between organisms
This had also given credibility to evolution
DNA evidence can be used to reinforce evidence of common ancestry based on anatomical similarities between species

10. Genetic Modification
This is carried out by gene transfer between species
It is possible to put one species’ genes into another’s genetic makeup
This is because DNA is universal

11. Methods of Acquiring New Combination of Genes
During the 1940’s it was discovered that 2 bacteria would form a tunnel like connection
Viruses can also carry bacterial genes from one bacteria to another
Bacteria can also “take-in” loose DNA from their surroundings
Recombinant DNA Technology – Combines genes from
different sources even
different species into a
single DNA molecule

12. Knowledge of Genomes have led to:
Making food more nutritious
Learning human genetics
Medicines

13. Biological Engineering
Engineering Bacteria
Plasmid – a small, circular DNA molecule separate from
the much larger bacterial chromosome
Acts just like a chromosome
Carries genes
Copies itself
When plasmid replicates, a copy can pass from one bacterial cell to another
Result is gene sharing among bacteria
This can help bacteria survive
For example resistance to antibiotics

14. Biological Engineering
Biologist use plasmids to move pieces of DNA into another bacteria
A plasmid is removed from a bacteria, biologist would insert the desired plasmid
Recombinant DNA – Transplanted plasmid becomes a
combination of original DNA and the
new DNA
Now plasmid is returned with the new combination of DNA where it reproduces many copies of the desired gene
AKA – Gene Cloning

15. Biological Engineering
Cut & Paste DNA
Gene removal from bacteria
1st – a piece of DNA containing the desired gene must be
“cut” out of a much larger DNA molecule
Restriction Enzymes – found in bacteria, protect bacteria
against intruding DNA from other
organisms and phages.
Restriction Enzymes recognize particular short nucleotide sequences; cuts sugar and phosphate bonds
Called Endonucleases

16. Biological Engineering
“Sticky Ends” – most restriction enzymes make staggered
cuts; the end that hangs at the end of
fragments are called “sticky end” because it
will bind to any complementary sequence.
“Sticky ends” bind to its complementary sequence
Using base pairing rules

17. Biological Engineering
DNA Ligase – enzyme, that “paste” the sticky ends
together.

18. Copying DNA
Clones are groups of genetically identical organisms, derived from a single original parent cell.
Copying DNA is more complex because a host cell is needed in addition to the cutting and pasting enzymes described above.
Yeast and the bacteria Escherichia coli are used as host cells
Plasmid is removed from host cell and cut open using a restrictor endonuclease (enzyme)
The gene to be copied is placed inside an open plasmid. (AKA gene splicing)

19. Copying DNA The DNA is pasted to the plasmid using DNA Ligase
Plasmid is now called a recombinant Plasmid
It can be used as a vector (a tool for introducing a new gene into an organic makeup)

20. Products from Genetically Engineered Microorganisms
Bacteria that break down chemicals or toxic waste – Oil Spills
Pesticides
Insulin
Used in the development of vaccines – Hepatitis B vaccine is made from Yeast cells – No side effects

21. Genetically Engineered Plants and Animals
Goal to improve characteristics of certain crops
Like delaying ripening, improve nutrition, resistance to spoilage or disease.
Genetically Modified Organism (GMO)
Any organism that has acquired one or more genes by artificial means
Transgenenic – When a GMO; is the source of genetic
material is from a different species.
Genetic engineering is replacing the traditional method of plant breeding

22. Genetically Engineered Plants and Animals
Genetically engineered eucalyptus trees in Sebring, FL used for paper
This flower was genetically engineered to produce insulin

23. Natural Methods of Cloning
Certain plants (strawberry) can send out horizontal structures to allow a new strawberry plant to grow a short distance from the original plant.
New plant will be an exact copy
If a potato is planted in the ground the new potato will be genetically identical to the plant
One animal that is capable of reproducing asexually by making clones of itself is the hydra (Hydra vulgaris)
Freshwater organism in the same phylum as sea jellies, sea anemones, and coral polyps.
If food sources are plenty buds on its body will form new genetically identical adults: hydra
Called budding
Hydra can sexually reproduce

24. Animals Cloned from Embryos
A clone is a group of identically identical organisms or group of cells
Derived from a single parent
Cloning occurring naturally in animals (including humans) you have identical twins
With the correct laboratory equipment: animals can be cloned at the embryo stage by breaking up the embryo into more than one group of cells
Can be twins, triplets, quadruplets, etc.
Essentially how we get twins

25. Genetically Engineered Plants and Animals
Used to make vaccines and growth hormones
Genetic modification is more difficult than in plants
Egg is removed – desired gene is injected
Mixed in test tube with sperm
Injected into womb to develop
Takes many attempts
If the offspring contains genes from a 3rd parent it may even be another species.
Dolly cloned January 1996
Roslin Institute in Scotland

26. Genetically Engineered Plants and Animals
How Researchers Produced Dolly:
From the original donor sheep to be cloned, a somatic cell (non-gamete cell) from the udder was collected and cultured. The nucleus was removed from a cultured cell.
An unfertilized egg was collected from another sheep and its nucleus was removed.
Using an electrical current, the egg cell and the nucleus from the cultured somatic cell were fused together.
The new cell developed in vitro in a similar way to a zygote and started to form an embryo.
The embryo was placed in the womb of a surrogate mother sheep.
The embryo developed normally
Dolly was born and was presented to the world as a clone of the original donor sheep

27. Genetically Engineered Plants and Animals
Reproductive Cloning – makes an entire individual (Dolly)
Somatic Cell Nuclear Transfer – removes a nucleus and it is replaced by another nucleus
the actual specific name of Dolly’s type of cloning

28. Genetically Engineered Plants and Animals
Goals:
Sheep with better quality wool
Pigs with leaner meat
Fish with faster maturing time
Huge Bulls (cows)
Cows that produce more milk
Producing hormones
Produce proteins

29. Cloning using undifferentiated cells
This is when scientist want to make copies of cells.
Therapeutic Cloning – aim to develop cells that have not yet gone through the process of differentiation
The cells are referred to as embryonic stem cells and the branch of laboratory work that investigates therapeutic cloning is called stem cell research.

30. Ethical Issues Surrounding Therapeutic Cloning
Production of human embryos for the sole purpose of medical research.
But this has lead to major breakthroughs in understanding human biology
We are currently able to grow cells:
Repair serious burns
New heart muscle to repair the heart
New kidney tissue