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Ch 13 genetic technology

Ch 13 genetic technology. Selective breeding. Choosing the best plants or animals for breeding

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Ch 13 genetic technology

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  1. Ch 13 genetic technology

  2. Selective breeding • Choosing the best plants or animals for breeding • It poses no threat to nature from man manipulating the course of nature. It has allowed our species to increase the efficiency of the animals and plants we breed, such as increasing milk yield from cows by continuously breeding selected cows with one another to produce a hybrid.

  3. Genetic technology • Increasing the frequency of desired alleles in a population

  4. inbreeding • Mating between closely related individuals to make sure breeds consistently exhibit a trait and to eliminate any undesired traits from breeding lines • Hybrid created • Overtime, results in physical and health defects. Harmful recessive traits will be expressed

  5. inbreeding • The breeding or mating of related individuals within an isolated or closed group of organisms or people. Inbreeding can result in inbreeding depression. However, in agriculture and animal husbandry, the continued breeding of closely related individuals can help to preserve desirable traits in a stock.

  6. Inbreeding depression • However, while it is an advantage both to the species and to humans to produce these desirable qualities that may benefit the organisms in question, continuous in-breeding and selective breeding of particular genes runs the risk of losing some of the other genes from the gene pool altogether, which is irreversible. This is called inbreeding depression, where the exclusivity of the advantageous genes mean that some other less desirable genes are phased out. In the long term, it is more advantageous for organisms to remain heterozygous

  7. Selective and inbreeding results • Genetic diversity in the long term is reduced, because many organisms end up with similar genomes due breeding with each other constantly. In normal circumstances, this process would be random, and would produce more variable offspring • With the above facts in hand, breeders need to produce more heterozygous offspring to ensure the long term welfare of the species they are breeding and their livelihood. The most important thing here is to preserve the genetic diversity of a species, and preferably keep the gene pool of a species as diverse as possible

  8. Human inbreeding • Marrying cousins in Pakistan • http://www.youtube.com/watch?v=Jfdn54wQnXI&feature=related

  9. Genetic engineering • Method of cutting DNA from one organism and inserting the DNA fragment into a host organism of the same of a different species • Increases the frequency of an allele • Cutting (cleaving) DNA from one organism into small fragments and inserting the fragments into a host organism of the same or a different species • Also known as recombinant DNA technology

  10. Genetic engineering • http://www.youtube.com/watch?v=zlqD4UWCuws • 3:37

  11. cloning • Genetically identical copies of an organism

  12. cloning • Dolly the Sheep • http://www.youtube.com/watch?v=-Qry1gYYDCA • 2:42

  13. Cloning humans • http://www.youtube.com/watch?v=7tbxN5uwaqA • 2:55

  14. Time Magazine Article • http://www.time.com/time/printout/0,8816,999233,00.html • Assignment: • Pros, Cons, your opinion

  15. Ethical issues concerning genetic engineering • http://www.youtube.com/watch?v=jY-868_HDbs • 6:03- Michael J Fox interview

  16. What are stem cells? • Unspecialized cells • Can undergo mitosis to remain stem cells • Embryonic stem cells can become specialized cells (any cell in the body) • “unlimited source of cells” “raw material for clinical or laboratory use”

  17. Embryonic stem cells • Embryonic stem cells. These stem cells come from embryos that are four to five days old. At this stage, an embryo is called a blastocyst and has about 150 cells. These are pluripotent (ploo-RIP-uh-tunt) stem cells, meaning they can divide into more stem cells or they can specialize and become any type of body cell. Because of this versatility, embryonic stem cells have the highest potential for use to regenerate or repair diseased tissue and organs in people.

  18. Where do embryonic stem cells come from? • The embryos being used in embryonic stem cell research come from eggs that were fertilized at in vitro fertilization clinics but never implanted in a woman's uterus because they were no longer wanted or needed. The excess embryos were frozen and later voluntarily donated for research purposes. The stem cells can live and grow in special solutions in test tubes or petri dishes in laboratories.

  19. Adult stem cells • Adult stem cells. These stem cells are found in small numbers in most adult tissues, such as bone marrow. Adult stem cells are also found in children and in placentas and umbilical cords. Because of that, a more precise term is somatic stem cell, meaning "of the body." Until recently, it was believed that adult stem cells could only create similar types of cells. For instance, it was thought that stem cells residing in the bone marrow could give rise only to blood cells. However, emerging evidence suggests that adult stem cells may be more versatile than previously thought and able to create unrelated types of cells after all. For instance, bone marrow stem cells may be able to create muscle cells. This research has led to early-stage clinical trials to test usefulness and safety in people.

  20. Why can’t researchers use adult stem cells instead of embryonic? • While research into adult stem cells is promising and moving forward rapidly, adult stem cells may not be as versatile and durable as embryonic stem cells are. Adult stem cells may not be able to be manipulated to produce all cell types, which limits how they can be used to treat diseases, and they don't seem to have the same ability to multiply that embryonic stem cells do. They're also more likely to contain abnormalities due to environmental hazards, such as toxins, or from errors acquired by the cells during replication. However, researchers have found that adult stem cells are more adaptable than was initially suspected. There have been significant advances in work with adult stem cells, and more studies are under way.

  21. Nuclear reprogramming • Adult cells altered to have properties of embryonic stem cells (induced pluripotent stem cells). Scientists have successfully transformed regular adult cells into stem cells using a technique called nuclear reprogramming. By altering the genes in the adult cells, researchers can reprogram the cells to act similarly to embryonic stem cells. This new technique may help researchers avoid the controversies that come with embryonic stem cells, and prevent immune system rejection of the new stem cells. But, it's not yet known if altering adult cells will cause adverse effects in humans. Researchers have been able to take regular connective tissue cells and reprogram them to become heart cells. The new heart cells were injected into mice with heart failure, where they improved heart function and survival time.

  22. Nuclear programming Time Magazine Article • http://www.time.com/time/specials/packages/article/0,28804,2101344_2100769_2100763,00.html

  23. Amniotic fluid stem cells • Amniotic fluid stem cells. Researchers have also discovered stem cells in amniotic fluid. Amniotic fluid fills the sac that surrounds and protects a developing fetus in the uterus. Researchers have identified stem cells in samples of amniotic fluid drawn from pregnant women during a procedure called amniocentesis. During this test, a doctor inserts a long, thin needle into a pregnant woman's abdomen to collect amniotic fluid. The fluid can be tested for abnormalities, such as Down syndrome, and fetal maturity. The procedure is generally considered safe for the developing fetus and the mother. More study of amniotic fluid stem cells is needed to understand their potential.

  24. Uses for stem cells • Promises for new medical treatments • Drug research testing • Tissue, organ repair

  25. What is a stem cell line? • A stem cell line is a group of cells that all descend from a single original stem cell. Cells in a stem cell line keep growing but don't differentiate into specialized cells. Ideally, they remain free of genetic defects and continue to create more stem cells. Clusters of cells can be taken from a stem cell line and frozen for storage or shared with other researchers. That way, researchers don't have to get stem cells from an embryo itself.

  26. What is stem cell therapy? • Stem cell therapy, also known as regenerative medicine, is the replacement of diseased, dysfunctional or injured cells with stem cells or their derivatives. It's somewhat similar to the organ transplant process but uses cells instead of organs. • Researchers grow stem cells in the lab. These stem cells are manipulated to make them specialize into specific types of cells, such as heart muscle cells, blood cells or nerve cells. This manipulation may involve changing the material in which the stem cells are grown or even injecting genes into the cells. The specialized cells could then be implanted into a person. For example, if the person had heart disease, the cells could be injected into the heart muscle. The healthy, transplanted heart cells could then contribute to repairing defective heart muscle. In fact, researchers have already shown that adult bone marrow cells guided to become heart-like cells can repair heart tissue in mice, and much more research is ongoing.

  27. Stem cells • http://www.youtube.com/watch?v=3Axkn8G18t8 • 9:50 • http://www.youtube.com/watch?v=8JTw2RpDo9o&feature=related • 6:15

  28. Embryonic stem cell research • http://www.youtube.com/watch?v=slh88WmR8QA • 1:23

  29. Stem Cell School • http://www.stemcellschool.org/

  30. How stem cells are changing how we think about disease • Time Magazine • http://www.time.com/time/specials/packages/article/0,28804,2059521_2059712_2059711,00.html

  31. Stem cell discovery worksheet • http://www.pbs.org/newshour/extra/teachers/lessonplans/science/adultstem_fact.pdf

  32. Stem cell web tour • http://www.jogtheweb.com/run/EmuKVsrGEA5i/Stem-Cells-Web-Tour

  33. Gel electrophoresis • Page 346

  34. Gene therapy • Insertion of normal genes into human cells to correct genetic disorders • http://www.youtube.com/watch?v=11maHFwC35s • http://www.youtube.com/watch?v=H0RvTOF1fEc

  35. DNA fingerprinting • Introns of DNA are unique to each individual. These patterns can be used like fingerprints to identify a person from whom they came. No two individuals (except identical twins) have the same DNA sequences. • Small DNA sample is obtained from suspect. Noncoding segments are cut into fragments by restriction enzymes and then separated by gel electrophoresis

  36. DNA fingerprinting • http://www.youtube.com/watch?v=RCI9YhstHK4 • http://www.youtube.com/watch?v=PSwlCk_Z02c • http://www.youtube.com/watch?v=Xq1_MF7F5is&feature=related

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