1. Georgia Performance Standards:
Genetic Engineering
Georgia Performance Standards:
Examine the use of DNA technology in
forensics, medicine, and agriculture
Essential Questions:
Should there be limits on how DNA technology is used?
How is DNA technology applied to solving problems?

2. Student Outcomes: How DNA comparison is used in forensic science
The process of genetic engineering through the use of recombinant DNA
Examine and question complex bioethical issues involving the use of DNA technology in modern medicine, industry, agriculture and forensics

3. Warm-up:
A New Breed
The tomatoes in your salad and the dog in your backyard are a result of selective breeding.
Over thousands of years, humans have developed breeds of animals and plants that have desirable characteristics.
How do breeders predict the results of crossing individuals with different traits?

4. Warm-up:
Think of two very different breeds of dogs that are familiar to you. On a sheet of paper, construct a table that has the following three heads: the name of each of the two dog breeds, and “Cross-Breed.”
2. The rows of the table should be labeled with characteristics found in both breeds of dogs. Examples might include size, color, type of coat, intelligence, aggression, and so on.
3. Fill in the column for each of the two dog breeds. In the column labeled “Cross-Breed,” write in the characteristic you would expect to see in a cross between the two breeds you have selected.

5. Selective Breeding
Selective Breeding- a method of improving a species by allowing only those individual organisms with desired characteristics to produce the next generation
Hybridization
Inbreeding

6. Hybridization:
Hybridization is a breeding technique that involves crossing different individuals to bring together the best traits of both organisms
Ex: combining the disease resistance of one plant with the food-producing capacity of another produces a hardier plant that increased food supply.

7. Inbreeding 
Inbreeding is the continued breeding of individuals with similar characteristics.
Used to maintain desired characteristics
Inbreeding helps to ensure that the characteristics that make each breed unique will be preserved.
Risks: Most of the members of a breed are genetically similar and genetic defects can arise.

8. Concept Map Selective Breeding consists of which crosses which crosses
Inbreeding
Hybridization
which crosses
which crosses
Similar
Organisms
Dissimilar
Organisms
for example
for example
Organism breed A
Organism breed B
which
which
Retains desired characteristics
Combines desired characteristics

9. Increasing Variation
Sometimes breeders want more variation than exists in nature.    
Breeders can increase the genetic variation in a population by inducing mutations, which are the ultimate source of genetic variability.
Radiation
Chemicals

10. Plant Breeding
 Drugs used in plant breeding sometimes cause plants to produce cells that have double or triple the normal number of chromosomes.
Plants grown from such cells are called polyploid because they have many sets of chromosomes.
Polyploidy produces larger and stronger plants, which increase the food supply for humans.

11. Checkpoint Questions:
Give one example of selective breeding.
Relate genetic variation and mutations to each other.
3. How might a breeder induce mutations?
4. What is polyploidy?
5. Suggest ways that plants could be altered to improve the world’s food supply.

12. Manipulating DNA: How are changes made to DNA?
Scientists use their knowledge of the structure of DNA and its chemical properties to study and change DNA molecules.
Different techniques are used:
to extract DNA from cells
to cut DNA into smaller pieces
to identify the sequence of bases in a DNA molecule
to make unlimited copies of DNA.

13. Genetic engineering
Genetic Engineering - making changes in the DNA code of a living organism.
Process:
DNA extraction
Cutting DNA
Separating DNA
Reading the sequence
Cutting and pasting
Making copies
Molecular
Biology

14. DNA Extraction How do biologists get DNA out of a cell?
DNA can be extracted from most cells by a simple chemical procedure:
The cells are opened and the DNA is separated from the other cell parts.

15. Cutting DNA
 DNA molecules from most organisms are much too large to be analyzed, so biologists cut them precisely into smaller fragments using restriction enzymes.
Restriction enzymes cut DNA at a specific sequence of nucleotides.
Very precise

16. Restriction Enzymes
This drawing shows how restriction enzymes are used to edit DNA.
The restriction enzyme EcoRI, for example, finds the sequence CTTAAG on DNA.
Then, the enzyme cuts the molecule at each occurrence of CTTAAG.
Different restriction enzymes recognize and cut different sequences of nucleotides on DNA molecules.
VIDEO

17. Separating DNA 
In gel electrophoresis, a mixture of DNA fragments is placed at one end of a porous gel, and an electric voltage is applied to the gel.
When the power is turned on, DNA molecules, which are negatively charged, move toward the positive end of the gel.
The smaller the DNA fragment, the faster it moves.
Uses:
Comparing genomes of different organisms or individuals.
Locating and identifying one particular gene out of the millions of genes in an individual’s genome.

18. Gel Electrophoresis Power source DNA plus restriction enzyme
Longer fragments
Shorter fragments
Mixture of DNA fragments
Gel

19. Using the Sequence of DNA:
“Reading” a DNA sequence is now an automated process.
The pattern of colored bands (Fluorescently labeled nucleotides) tells the exact sequence of bases in the DNA.
Each color corresponds to a specific nucleotide base (A, G, C, and T)

20. DNA Sequencing Power source Gel Single strand of DNA Fluorescent dye
Strand broken after A
Strand broken after C
Strand broken after G
Strand broken after T
Power source
Gel

21. Cutting and Pasting 
Enzymes make it possible to take a gene from one organism and attach it to the DNA of another organism.
Such DNA molecules are sometimes called recombinant DNA because they are produced by combining DNA from different sources.

22. Making Copies PCR Process:
1. DNA is heated to separate strands
2. DNA is cooled to allow primers to bind
3. DNA polymerase copies the strands
In order to study genes, biologists often need to make many copies of a particular gene.
A technique known as polymerase chain reaction (PCR) allows biologists to make copies of DNA.

23. PCR:
Polymerase Chain
Reaction
VIDEO

24. Checkpoint Questions:
Describe the process scientists use to manipulate DNA.
2. Why might a scientist want to know the sequence of a DNA molecule?
3. How does gel electrophoresis work?
4. Which technique can be used to make multiple copies of a gene? What are the basic steps in this procedure?
5. How is genetic engineering like computer programming?

25. Cell Transformation
During Cell Transformation, a cell takes in DNA from outside the cell.
Plant and animal
This external DNA becomes a part of the cell’s DNA.
One way to make recombinant DNA is to insert a human gene into bacterial DNA.
The new combination of genes is then returned to a bacterial cell, and the bacteria can produce the human protein.
video

26. Transforming Bacteria
Recombinant DNA is used.
The foreign DNA is first joined to a small, circular DNA molecule known as a plasmid.
Plasmids have a DNA sequence that serves as a bacterial origin of replication.
Plasmids have a genetic marker—a gene that makes it possible to distinguish bacteria that carry the plasmid from those that don’t.

27. Transforming Bacteria

28. Plant Cell Transformation
Recombinant plasmids can be used to infect plant cells.
DNA can also be injected directly into some plant cells.
Cells transformed by either procedure can be cultured to produce adult plants.    

29. Plant Cell Transformation
Agrobacterium tumefaciens
Gene to be transferred
Cellular DNA
Inside plant cell, Agrobacterium inserts part of its DNA into host cell chromosome
Recombinant plasmid
Plant cell colonies
Transformed bacteria introduce plasmids into plant cells
Complete plant is generated from transformed cell

30. Animal Cell Transformation: Knockout Genes
Recombinant DNA can replace a gene in an animal’s genome.
The ends of the recombinant DNA recombine with sequences in the host cell DNA.
When the recombinant DNA is inserted into the target location, the host cell’s original gene is lost or knocked out of its place.

31. Knockout Genes

32. Checkpoint Questions:
What is transformation?
How can you tell if a transformation experiment has been successful?
3. How are genetic markers related to transformation?
4. What are two features that make plasmids useful for transforming cells?
5. Compare the transformation of a prokaryotic cell with the transformation of a eukaryotic cell.

33. Applications of Genetic Engineering
Scientists have developed many transgenic organisms, which are organisms that contain genes from other organisms.
scientists have removed a gene for green fluorescent protein from a jellyfish and tried to insert it into a monkey.

34. Applications of Genetic Engineering
Transgenic animals are often used in research.
What might be the benefit to medical research of a mouse whose immune system is genetically altered to mimic some aspect of the human immune system?
Transgenic plants and animals may have increased value as food sources.
What might happen to native species if transgenic animals or plants were released into the wild?

35. Transgenic Organisms:
The universal nature of genetic mechanisms makes it possible to construct organisms that are transgenic, meaning that they contain genes from other organisms.
A gene from one organism can be inserted into cells from another organism.
These transformed cells can then be used to grow new organisms.

36. Transgenic Bacteria or Yeast:
Transgenic bacteria reproduce rapidly and are easy to grow.
Therefore they now produce a host of important substances useful for health and industry.
human insulin, growth hormone, and clotting factor

37. Transgenic Animals:
Transgenic animals have been used to study genes and to improve the food supply
Strains of mice
produced with human genes that make their immune systems act similarly to those of humans.
study the effects of diseases on the human immune system.
Transgenic livestock
produced with extra copies of growth hormone genes.
such animals grow faster and produce meat that is less fatty than that from ordinary animals.
Transgenic chickens
resistant to the bacterial infections that sometimes cause food poisoning.

38. Transgenic Plants: Human antibodies that can be used to fight disease;
Transgenic plants help to increase our food supply.
Genes produce a natural insecticide (this avoids synthetic pesticide use).
Genes that enable them to resist weed-killing chemicals (allows farmers to grow more food by controlling weeds.
Human antibodies that can be used to fight disease;
Plastics that can now be produced only from petroleum
Foods that are resistant to rot and spoilage.

39. Cloning:
A clone is a member of a population of genetically identical cells produced from a single cell.
Cloned colonies of bacteria and other microorganisms are easy to grow, but this is not always true of multicellular organisms, especially animals.

40. Cloning:
Clones are used for medical and scientific value, but also causes ethical issues.
In 1997, Scottish scientist Ian Wilmut stunned biologists by announcing that he had cloned a sheep

41. Cloning A body cell is taken from a donor animal.
An egg cell is taken from a donor animal.
The nucleus is removed from the egg.
The body cell and egg are fused by electric shock.
The fused cell begins dividing, becoming an embryo.
The embryo is implanted into the uterus of a foster mother.
The embryo develops into a cloned animal.

42. Cloning of the First Mammal
Section 13-4
A donor cell is taken from a sheep’s udder.
Donor Nucleus
These two cells are fused using an electric shock.
Fused Cell
Egg Cell
The nucleus of the egg cell is removed.
An egg cell is taken from an adult female sheep.
The fused cell begins dividing normally.
Cloned Lamb
Embryo
The embryo develops normally into a lamb—Dolly
The embryo is placed in the uterus of a foster mother.
Foster Mother
Go to Section:

44. Checkpoint Questions:
1. List one practical application for each of the following: transgenic bacteria, transgenic animals, transgenic plants.
2. What is a transgenic organism?
3. What basic steps were followed to produce Dolly?
4. List reasons you would or would not be concerned about eating genetically modified food.

45. Warm-up:
As you become more aware of scientific advances in genetics, you might realize that with the ability to manipulate genes, there comes responsibility.
This ability provides an opportunity to improve the lives of many people.
But there is also a potential for errors or intentional misuse of the technology.

46. Warm-up: Working with a partner, answer the following questions.
1. In what type of situation do you think genetic engineering—changing the genes of organisms—is warranted? Explain your reasoning about your position. If you do not think that genetic engineering is ever warranted, explain your reasons for your position.
2. In what type of situation do you think genetic engineering might be misused? Suggest limits that might be placed on the manipulation of genes to avoid its misuse.

47. DNA fingerprinting
Analysis of sections of DNA that have little or no known function, but vary widely from one individual to another, in order to identify individuals
The reliability of DNA evidence has helped convict criminals as well as overturn many convictions.

48. Figure 14-18 DNA Fingerprinting
Section 14-3
Restriction enzyme
Chromosomes contain large amounts of DNA called repeats that do not code for proteins. This DNA varies from person to person. Here, one sample has 12 repeats between genes A and B, while the second sample has 9 repeats.
Restriction enzymes are used to cut the DNA into fragments containing genes and repeats. Note that the repeat fragments from these two samples are of different lengths.
The DNA fragments are separated according to size using gel electrophoresis. The fragments containing repeats are then labeled using radioactive probes. This produces a series of bands—the DNA fingerprint.
Go to Section:

49. The Human Genome Project:
The Human Genome Project is an attempt to sequence all human DNA.
VIDEO

50. Gene Therapy Curing genetic disorders by gene therapy.
Gene therapy is the process of changing the gene that causes a genetic disorder.    
In gene therapy, an absent or faulty gene is replaced by a normal, working gene.
This way, the body can make the correct protein or enzyme it needs, which eliminates the cause of the disorder.

51. Figure 14-21 Gene Therapy Section 14-3 Go to Section: Bone marrow cell
Normal hemoglobin gene
Nucleus
Chromosomes
Bone marrow
Genetically engineered virus
Go to Section:

52. Think About It…
What will happen to the human species if we gain the opportunity to design our bodies…

53. Checkpoint Questions:
What is the Human Genome Project?
 Describe how gene therapy works.
3. Name two common uses for DNA testing.
4. Describe how molecular biologists identify genes in sequences of DNA.
5. Do you think it should be legal for people to use genetic engineering to affect their children’s characteristics? Give reasons for your answer.