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Biotechnology. selective breeding when the plants/animals from the existing stock that have the characteristics they want are selected and are allowed.

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Presentation on theme: "Biotechnology. selective breeding when the plants/animals from the existing stock that have the characteristics they want are selected and are allowed."— Presentation transcript:

1 Biotechnology

2 selective breeding when the plants/animals from the existing stock that have the characteristics they want are selected and are allowed to breed. Uses: * High yielding crops, such as wheat are produced by collecting the seeds from only the plants that have a good yield of wheat. * Disease resistant crops can be developed. * Animals on farms are bred so that they produce more food, e.g. cows with better meat, hens that lay more eggs. * Animals such as dogs and cats are bred for fashion. They may also be bred to do a particular job (e.g. sheepdogs).

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4 Disadvantage: There are many ethical concerns where people claim that we are 'acting as God' and it is somehow immoral. There is also the risk of mutation which could lead to unwanted consequences.

5 Impact on society: The impact on society will depend on the extent of where the manipulation of plants and animals is taken. If it is generally mild, the majority of society may accept it, however there are also ethical issues involved and religious groups could be strongly against it.

6 Inbreeding reproduction from the mating of two genetically related parents, which can increase the chances of offspring being affected by recessive traits.

7 Test cross the cross of an organism with an unknown dominant genotype with an organism that is homozygous recessive for that trait

8 1. The process of breeding plants and animals to have desired traits is know as SELECTIVE BREEDING _ 2. Examples of this are things like: PURE BREED DOGS, PLANTS WITH A SPECIFIC TASTE,OR RESISTANT TO DISEASE. 3. Organisms whose parents have different forms of a trait are known as what? HYBRIDS 4. Selective breeding can be done between 2 closely related organisms and is called INBREEDING

9 5. What is a disadvantage of this process? HARMFUL TRAITS CAN BE PASSED ON 6. When a test cross is done it is done to determine the GENOTYPE of one organism by crossing it with an organism whose genotype is known and is HOMOZYGOUS RECESSIVE. 7. If the example of a white grapefruit is used like in the book, what results would indicate that the parent white grapefruit is heterozygous? ½ OF THE OFFSPRING WOULD BE WHITE AND ½ WOULD BE RED IF THE PARENT WAS HETEROZYGOUS AND NOT HOMOZYGOUS

10 Genetic engineering 1. What is genetic engineering? A WAY TO MANIPULATE DNA BY INSERTING EXTRA DNA OR DNA FROM ANOTHER ORGANISM

11 Genetic Engineering Genetic engineers manipulate DNA for practical purposes. Restriction enzymes cleave DNA into fragments that have short sticky ends. Sticky ends allow DNA fragments from different organisms to join together to form recombinant DNA. 2. What is the name for all of the DNA present in the nucleus of a cell? GENOME

12 Restriction enzyme proteins made by bacteria that can cut DNA at specific places

13 Recombinant DNA DNA made from combining DNA from 2 or more different sources.

14 Plasmid A small circular, double stranded DNA molecule found in bacterial cells used as a vector to get recombinant DNA into a host cell.

15 7. In order to get the recombinant DNA into the host cell a vector is needed, a PLASMID is a small circular piece of DNA that can be cut with restriction enzymes and then the gene can be inserted and joined with DNA ligase. 8. The plasmid gets into the bacterial cell by TRANSFORMATION when the cell is heated or shocked electrically.

16 Cloning When the bacterial cell copies its own DNA it also copies the plasmid and any recombinant DNA inserted in the plasmid. This is called cloning the DNA. Multiple copies of the DNA can be made this way. 6. Bacteria are often the host cell for doing what to the new DNA? COPY IT/clone it! 9. Bacteria will copy the plasmid along with their own DNA and this is how CLONING occurs.

17 PCR PCR (polymerase chain reaction) is a method to analyze a short sequence of DNA (or RNA) even in samples containing only minute quantities of DNA or RNA. PCR is used to reproduce (amplify) selected sections of DNA or RNA. DNARNA

18 PCR Animation http://users.ugent.be/~avierstr/principles/pcrani.html Denaturation: At 94 C (201.2 F), the double-stranded DNA melts and opens into two pieces of single-stranded DNA. Annealing: At medium temperatures, around 54 C (129.2 F), the primers pair up (anneal) with the single-stranded "template" (The template is the sequence of DNA to be copied.) On the small length of double-stranded DNA (the joined primer and template), the polymerase attaches and starts copying the template. Extension: At 72 C (161.6 F), the polymerase works best, and DNA building blocks complementary to the template are coupled to the primer, making a double stranded DNA moleculemolecule

19 10. When a scientist mixes an unknown sample of DNA with DNA polymerase and tagged A,C,G and T what are they trying to do? DETERMINE THE SEQUENCE OF THE DNA 11. PCR stands for what? POLYMERACE CHAIN REACTION 12. What does PCR do? MAKE MILLIONS OF COPIES OF A SPECIFIC REGION OF A DNA FRAGMENT

20 6. Transgenic organism Organisms that have had genes from other species inserted into their genome There are ethical and health concerns regarding this practice… GMO: An organism whose genetic characteristics have been altered by the insertion of a modified gene or a gene from another organism using the techniques of genetic engineering.

21 Virtual lab on biotechnology http://www.montereyinstitute.org/courses/ AP%20Biology%20I/course%20files/multi media/chapter9virtuallab02/lessonp.htmlhttp://www.montereyinstitute.org/courses/ AP%20Biology%20I/course%20files/multi media/chapter9virtuallab02/lessonp.html

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24 DNA fingerprinting The use of gel electrophoresis to identify sections of DNA that are unique to an individual. Nova DNA virtual lab http://www.teachersdomain.org/asset/tdc0 2_int_creatednafp2/http://www.teachersdomain.org/asset/tdc0 2_int_creatednafp2/

25 Gel electro virtual lab http://learn.genetics.utah.edu/content/labs/ gel/http://learn.genetics.utah.edu/content/labs/ gel/

26 Electrophoresis uses an electric field within a gel to separate DNA fragments by their size..

27 Gene therapy A way of fixing mutated genes by inserting normal genes to replace the mutated ones. Human Genome project link http://www.ornl.gov/sci/techresources/Human_Genome/project/about.sh tmlhttp://www.ornl.gov/sci/techresources/Human_Genome/project/about.sh tml Researchers also are experimenting with introducing a 47th (artificial human) chromosome into target cells. This chromosome would exist autonomously alongside the standard 46 --not affecting their workings or causing any mutations. It would be a large vector capable of carrying substantial amounts of genetic code, and scientists anticipate that, because of its construction and autonomy, the body's immune systems would not attack it. A problem with this potential method is the difficulty in delivering such a large molecule to the nucleus of a target cell.

28 What factors have kept gene therapy from becoming an effective treatment for genetic disease? Short-lived nature of gene therapy - Before gene therapy can become a permanent cure for any condition, the therapeutic DNA introduced into target cells must remain functional and the cells containing the therapeutic DNA must be long-lived and stable. Problems with integrating therapeutic DNA into the genome and the rapidly dividing nature of many cells prevent gene therapy from achieving any long-term benefits. Patients will have to undergo multiple rounds of gene therapy. Immune response - Anytime a foreign object is introduced into human tissues, the immune system is designed to attack the invader. The risk of stimulating the immune system in a way that reduces gene therapy effectiveness is always a potential risk. Furthermore, the immune system's enhanced response to invaders it has seen before makes it difficult for gene therapy to be repeated in patients. Problems with viral vectors - Viruses, while the carrier of choice in most gene therapy studies, present a variety of potential problems to the patient --toxicity, immune and inflammatory responses, and gene control and targeting issues. In addition, there is always the fear that the viral vector, once inside the patient, may recover its ability to cause disease. Multigene disorders - Conditions or disorders that arise from mutations in a single gene are the best candidates for gene therapy. Unfortunately, some the most commonly occurring disorders, such as heart disease, high blood pressure, Alzheimer's disease, arthritis, and diabetes, are caused by the combined effects of variations in many genes. Multigene or multifactorial disorders such as these would be especially difficult to treat effectively using gene therapy. For more information on different types of genetic disease, see Genetic Disease Information.Genetic Disease Information http://www.ornl.gov/sci/techresources/Human_Genome/medicine/genetherapy.shtml

29 Ethical questions about gene therapy What is normal and what is a disability or disorder, and who decides? Are disabilities diseases? Do they need to be cured or prevented? Does searching for a cure demean the lives of individuals presently affected by disabilities? Is somatic gene therapy (which is done in the adult cells of persons known to have the disease) more or less ethical than germline gene therapy (which is done in egg and sperm cells and prevents the trait from being passed on to further generations)? In cases of somatic gene therapy, the procedure may have to be repeated in future generations. Preliminary attempts at gene therapy are exorbitantly expensive. Who will have access to these therapies? Who will pay for their use?

30 . The Food and Drug Administration (FDA) has not yet approved any human gene therapy product for sale. Current gene therapy is experimental and has not proven very successful in clinical trials. Little progress has been made since the first gene therapy clinical trial began in 1990. According to the human genome project web site!. http://www.ornl.gov/sci/techresources/Human_Geno me/medicine/genetherapy.shtml#status


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