Biotechnology Final Exam Review Questions

 Biotechnology Final Exam Review Questions  1. What is the source of embryonic stem cells? How are they obtained?  Blastocysts (Inner cell mass of a fertilized egg), obtained from human embryo lol.  They can be cultured (CULTIVATED) in vitro.  How embryonic stem cells are obtained (in vitro fertilization: - When fertilization is successful, the sperm head bearing the nucleus enters the egg. The fertilized egg divides until a multicellular ball of cells (a blastocyst) is formed. The inner cell mass of this blastocyst contains the embryonic stem cell. In vitro fertilization of egg via sperm creates blastocyst. Blastocyst harvested from the womb of a woman. 2. What are the major problems encountered in attempts to clone mammals?  “Even though clones are exact genetic duplicates, they are not exactly identical to the original in other ways.  Animals are shaped by their experiences and environments as well as their genes” (178) “The present success rate for cloning is actually quite low” (178).  Problems include many clones being born with defects, as well as surrogate mothers having a higher mortality rate.   “Clones may be old before their time” (179).  The telomere length for Dolly were similar to her adult donor rather than other newborn halves. Not exactly identical (environmental factors). Defect rates higher. High surrogate mother mortality rate. Issue with family tree (sister/daughter. brother/son). Clones may be older. Clone Wars 3. Explain the concept of knockout animals. How are they used in medical research? |Knockouts have been genetically engineered so that a specific gene is disrupted… an active gene is replaced with DNA that has no functional information. When the gene is knocked out of place by the useless DNA, the trait controlled by the gene is eliminated from the animal.” (184).   Knockouts can be used to test the effects of certain genes (what would happen if they disappear) “...we have a clear idea of the function of the gene” (184). We can see what happens when a gene is damaged or absent. Creation of titties cancer mice, who were used to test treatments. Replace active gene with nonfunctional DNA strand. Remove trait expressed. Checks effects of certain genes. 4. Briefly describe how the human genome project will result in advances in medical biotechnology. Human Genome Project: the project to identify all genes (the genome), contained in the DNA of human cells and to map their locations to each of the 24 human chromosomes.  The Human Genome Project has provided unlimited potential for the development of new diagnostic approaches for detecting disease and molecular approaches for treating and curing human genetic disease conditions  Gene expression and Loci identification. Help with detecting and treating genetic disease. 5. What is gene therapy? Distinguish between ex vivo and in vivo gene therapy. Describe specific examples.  Gene Therapy: “involves the delivery of therapeutic genes into the human body to correct disease conditions created by a faulty gene or genes” (275).   Ex vivo: “cells from a person with a disease condition are removed from the patient, treated in a laboratory using techniques similar to bacterial transformation, and then reintroduced into the patient” (275).  Leukemia and other cancers. In vivo: Introducing genes directly into tissues and organs without removing the cells from the body.   Used for eye diseases. Gene Therapy: Treat disease via therapeutic genes. Ex vivo: Remove and fix, put back. In vivo: Put genes directly into body. 6. Describe one of the processes used to insert new genes into plants. Provide two examples of genetically enhanced plants.  Gene guns are typically used to shoot DNA into the nucleus of a plant cell, but they can also be aimed at the  chloroplast,  the part of the cell that contains chlorophyll Plants have between 10 and 100 chloroplasts per cell, and each chloroplast contains its own bundle of DNA. Whether they target the nucleus or the chloroplast, researchers must be able to identify the cells that have incorporated the new DNA. In one common approach, they combine the gene of interest with a gene that makes the cell resistant to certain antibiotics. This gene is called a marker gene  or reporter gene. After firing the gene gun, the researchers collect the cells and try to grow them in a medium that contains a specific antibiotic. Only the genetically transformed cells will survive. The antibiotic-resistant gene can then be removed before the cells grow into mature plants, if the researcher so desires. Two examples of genetically enhanced plants are Golden Rice and Flavr Savr tomatoes (antisense technology). Gene gun shoots DNA into the Nucleus or Chloroplast of plant. Examples include Golden Rice and Flavr Savr tomatoes. (Nerd example: Antibiotic-resistant gene put in plant cells. Collect cells and put in antibiotic medium. Collect only the antibiotic-resistant cells) 7. Discuss the applications of biotechnology to rice, soybeans and corn.  Golden Rice: has more beta carotene, a provitamin that the body converts to vitamin A. Disease and herbicide resistant. Bt corn: disease and herbicide resistant Soybeans: herbicide tolerant, high-performance cooking oils 8. Explain how the invention of PCR and the discovery of restriction enzymes (endonucleases) revolutionized biotechnology.  Polymerase Chain Reaction allowed for the easy cloning of target DNA strands that can then be used for a variety of  (https://www.youtube.com/watch?v=hO3mTqrEeq8 PCR in 2 min) Restriction enzymes: Restriction enzymes are DNA-cutting enzymes that made gene cloning and recombinant DNA techniques possible In the simplest sense, the discovery of restriction enzymes provided molecular biologists with the “scissors” needed to carry out gene cloning.  PCR makes cloning easier. Restriction enzyme makes targeted cloning of genes easier. 9. Discuss the pros and cons of using human embryonic stem cells in research to find cures for diseases.  Pro:  They last forever (no aging) Grow rapidly and can be frozen They can be manipulated into any type of cell, allowing for testing on virtually anything Understanding the development of the human species Con: Hard to obtain cells if they are not cultured Ethical concerns over killing the embryo to obtain the cells needed Expensive Needs more research 10. An experiment in England produced headless tadpole embryos. The researcher said that this could potentially be done in humans. An issue of Science contained a letter to the editor stating that “the cloning of headless-humans as sources of organs for transplant is absurd on both scientific and moral grounds.” Discuss the merits of the research and its relationship to humans. Is the statement in the letter accurate? Why?  Discuss using your own opinions Pro: Will allow for saving more lives through the surplus of human organs No rejection if linked directly with original DNA donor Con: Ethical Issues (Is it a human?) Age of organs (Refer to cloning problems above) 11. Describe the roles of two of the federal agencies involved in the regulation of genetically modified organisms.  FDA: regulates foods on the market, the USDA oversees growing practices,   EPA: controls the use of Bt proteins and other so-called pesticides. Broken into food and pesticide production/usage.  12. What are the advantages and limitations of bioremediation? Provide concrete examples.  Advantage: it uses decomposers and green plants, or their enzymes to improve the condition of contaminated environment.  Promising option for remediation since it is effective and economic in removing oil with less environmental damage. (Bioremediation enhances the ability of microorganisms and the microbes essentially treat oil as their food) Limitations: The process of bioremediation is slow and requires time. It cannot clean or eliminate heavy metals and other contaminants. Advantage: Eco-friendly, Effective and Cheap. Limitations: Slow/time-consuming. Can’t clean all contaminant types. 13. Describe the role of the Bt gene in plant biotechnology. Bacillus thuringiensis (Bt) produces a crystallized protein that kills harmful insects and their larvae.  The Cry gene causing this event is the subject of an expanding market of “insect-resistant” genetically engineered plants. By spreading spores of the bacterium across their fields, farmers can protect their crops without using harmful chemicals. farmers can grow plants containing Bt genes.  Plants that contain the gene for the Bt toxin have a built-in defense.  This biotechnologically enhanced pesticide has been successfully introduced into a wide range of plants, including tobacco, tomatoes, corn, and cotton. In fact, most soybean seeds planted today contain the gene for Bt toxin, which effectively kills cotton-infesting insects. Bt produces insect killing proteins. Easy to introduce “Cry gene” to crops. Works in a wide variety of plants. (Soybeans majority Bt crop) 14. Largely through the world-wide efforts of the World Health Organization, smallpox was finally eradicated in 1979. Today, there are only two known stocks of smallpox, one at the CDC (Centers for Disease Control and Prevention) in Atlanta, GA, and the other in Russia. There has been an ongoing and contentious controversy as to whether these last remnants of smallpox should be destroyed. Please discuss in detail the reasons that you believe the smallpox genome should remain or should be destroyed.  Discuss using your own opinions Keep: Allows for future research and innovation in microbiology Develop vaccine if smallpox returns stronger Destroy: Risk of another smallpox outbreak Weaponization 15. In 2002 a research lab in the US synthesized from scratch an infectious polio virus (using mail order DNA and two years of work). While the polio genome is small (7740 bp) do you think that it is conceivable that the smallpox (185,000 bp genome) could be synthesized? Discuss. Should the creation of the polio virus by synthesis been performed in the first place?  Wtf???haha Possible: Yes, I mean why not? It’ll just take longer than polio.   Impossible: Nah, too long. Genome also isn’t mapped. Yes it should have been made: Do it before the baddies can do it? No it shouldn’t have: Playing with fire. Encouraging bioterrorism 16. Explain how the clone, Dolly, was produced.  1. Donor cells removed from mammary gland 2. Donor cells starved in low-nutrient culture medium 3. Egg cell removed from donor 4. Nucleus removed using micropipette 5. Donor cell and egg cell fused using electrical pulses 6. Cell is then fertilized, cell division starts 7. New embryo is implanted into surrogate mother 8. Dolly ?????? Harvest cells from mammary gland and place in nutrient medium. Add donor cells to nucleus-free egg. Fertilize egg and implant in surrogate mother. 17. Which regions of the human genome are used for forensic investigations? Why?  Short Tandem Repeats are used.  Each person has different variations of the STR’s that are unique, creating a “DNA fingerprint.” STRs are unique in each person.   18. In your opinion, which would have a more negative impact on the environment: a BT gene that escapes into weedy relatives of crop plants or the continued large-scale use of synthetic pesticides to protect plants from the European Corn Borer? Support your position.  Discuss using your own opinion Bt worse:  Bt has a chance of changing the nutritional value of wild plants.  If Bt changes weeds and subsequently the bottom of the food chain, it has a chance to destabilize the food chain/ecosystem.   If herbicide/pesticide resistant Bt transfers to weeds, you can’t kill the weeds anymore.  Bt kills endangered butterflies  Pesticides Worse: Studies show that pesticide use can affect ecosystems outside of direct exposure to crop land.  Runoff and water pollution concerns actually proven.  Bt pollen won’t get to lethal levels for butterflies  19. Describe one of the techniques used to produce transgenic animals.  Retrovirus-mediated transgenesis: infect mouse embryos with retrovirus before implanting embryos, retrovirus is a vector for new DNA. Transgenic sheep and goats have been produced that express foreign proteins in their milk. Transgenic chickens are now able to synthesize human proteins in the "white" of their eggs. Pronuclear microinjection: introduces transgene DNA at the earliest possible stage of development of the zygote.  Sperm and cell join, DNA injected directly into either the nucleus of sperm or egg. No vector is required, no external genetic sequence to muddle the process. Embryonic stem cell method: embryonic stem cells are collected and mixed with DNA.  some of the ES cells will absorb DNA and be transformed.  Transformed cells will be injected into the inner cell mass. Sperm-mediated transfer: uses “linker proteins” to attach DNA to sperm cells.  Sperm fertilizes an egg, it carries the valuable genes along with it.   Gene Guns: typically used to shoot DNA into the nucleus of a plant cell, but they can also be aimed at the  chloroplast,  the part of the cell that contains chlorophyll Pick one and write about it. 20. One definition for organic agriculture is “Food production that avoids the use of synthetic herbicides, pesticides or fertilizers.” Given this definition, do you think that BT-crops can be integrated into the framework of organic agriculture? Be sure to state explicitly whether or not you believe BT-crops fit within the definition of organic agriculture and why. Provide concrete examples of how BT-crops are or are not compatible with this definition of organic agriculture. (Keep in mind: Organic farmers already use BT-toxin derived from bacteria as insecticides.)  Discuss using your own opinions, idk about examples Read Pg. 196 (or 162)  from Plant Biotechnology: Practical Applications: Genetic Pesticides  Easier to argue it is organic. Technically plant has built-in pesticides. 21. Compare and contrast genes and chromosomes, and describe their roles in the cell.  Genes are composed of DNA sequences while chromosomes are entire DNA strands that are packed tightly together so they can fit into a cell. So, the entire chromosome is lined with genes. In other words, one chromosome contains several genes, while that cannot be said the other way around. Genes are a section of the DNA that are in charge of different functions like making proteins. Chromosomes tightly bind DNA to make it fit inside the cell and are used to ensure that DNA is correctly replicated during cell division  Genes are a small part of DNA. Chromosomes are the entire DNA strand. Genes code for proteins. Chromosomes vital for cell division. 22. Name three therapeutic recombinant proteins produced in bacteria and explain what they are used for. Insulin — keeps diabetics alive long enough to eat another donut Therapeutic proteins—such as monoclonal antibodies, blood proteins, and enzymes produced by living organisms to fight disease—can also be thought of as biotech drugs.  Interferon - are a group of signaling proteins made and released by host cells in response to the presence of several viruses. Interleukins -  is a kind of cytokine, which plays a critical role in immunological regulation and homeostasis. It is originally discovered from leukocytes Anticoagulants- Prevent blood clots (blood thinners) Pick 3