1. Genetic technology
Unit 4
Chapter 13

2. Selective Breeding
Choosing plants and animals with the most desired traits to be parents of the next generation
Increases amount of desired genes in a population
Inbreeding is mating between closely related individuals and ensures pure lines.
Overtime, inbreeding is detrimental because of deleterious recessive genes.

3. Selective breeding common in dogs and horses.

4. Hybrid vigor
A hybrid is the offspring of parents that have different forms of a trait.
Hybrids produced by crossing two purebred plants are often larger and stronger than their parents.
Plants are often hybrids.

5. Test cross
a method of breeding dominant phenotype individual to homozygous recessive individual to determine the dominant individual’s genotype
If the organism being tested is heterozygous, the expected 1:1 phenotypic ratio will be observed.

6. Genetic engineering
and more reliable method for increasing the frequency of a specific allele in a population
Recombinant DNA technology: cutting (cleaving) DNA from one organism into small fragments and inserting the fragments into a host organism of the same or a different species

7. Transgenic organisms
Plants and animals that contain functional recombinant DNA from an organism of a different genus are known as transgenic organisms because they contain foreign DNA.

8. Steps for recombining DNA
Isolate the foreign DNA fragment that will be inserted using restriction enzymes
bacterial proteins that have the ability to cut both strands of the DNA molecule at a specific nucleotide sequence called palindromes
Attach the DNA fragment to a carrier
Transfer into the host organism

9. Recombinant DNA technology

10. Restriction enzyme action
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11. Click on image to play video.
Vector
Mechanical or biological way for DNA from one species to be carried into a host cell
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12. Gene cloning
After foreign DNA has been inserted into a plasmid, the recombined DNA is transferred into a bacterial cell.
Advantage: Bacteria reproduce quickly and can produce millions of copies of the recombinant DNA.
Each identical recombinant DNA molecule is called a gene clone.

13. Gene cloning using plasmid vectors

14. Cloned animal – Dolly the sheep

15. Polymerase chain reaction
Method to copy DNA outside of a living organism host
Heat, enzymes, and nucleotides are mixed in a machine to make multiple DNA copies.

16. Sequencing DNA
Machines in laboratories can determine the nucleotide order of small DNA fragments.
The DNA sequence can be visualized using gel electrophoresis techniques.

17. The entire human genome has been sequenced.
In 1990, scientists in the United States organized the Human Genome Project (HGP). It is an international effort to completely map and sequence the human genome, the approximately genes on the 46 human chromosomes.
In February of 2001, the HGP published its working draft of the 3 billion base pairs of DNA in most human cells.
The sequence of chromosomes 21 and 22 was finished by May 2000.

18. Gel electrophoresis
DNA cut with restriction enzymes are loaded into a gel.
Electric currents separate the DNA fragments.
DNA from two sources can be compared for similarities.

19. Loading gel

20. Applying electric field to separate DNA

21. Comparing DNA fragments for similarities

22. DNA fingerprinting
DNA fingerprinting can be used to convict or acquit individuals of criminal offenses because every person is genetically unique

23. Recombinant DNA technology in society
Scientists have modified the bacterium E. coli to produce the expensive indigo dye that is used to color denim blue jeans.
Pharmaceutical companies already are producing molecules made by recombinant DNA to treat human diseases

24. Recombinant technology in society
Recombinant bacteria are used in the production of human growth hormone to treat pituitary dwarfism.
Also, the human gene for insulin is inserted into a bacterial plasmid by genetic engineering techniques. Recombinant bacteria produce large quantities of insulin
Scientists can study diseases and the role specific genes play in an organism by using transgenic animals
Crops have been developed that are better tasting, stay fresh longer, and are protected from disease and insect infestations

25. Gene therapy
Gene therapy is the insertion of normal genes into human cells to correct genetic disorders