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21 Cards in this Set
- Front
- Back
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What is PCR (polymerase chain reaction) used for?
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copy and amplify tiny quantities of DNA. Very useful if you only have a small sample of DNA (like from a blood sample from a patient or a crime scene) and you need lots of DNA to do DNA profiling.
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How does gel electrophoresis work?
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Gel electrophoresis is used to separate DNA (or other molecules) by theis size and charge. The DNA fragments move in an electric field. The negatively charged DNA all moves towards the positive electrode. Small pieces move farther than large pieces.
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What biotechnology applications is gel electrophoresis useful for?
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DNA profiling
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What applications is DNA profiling used for?
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Forensic investigations (matching blood at a crime scene to a suspect), paternity testing (determining the father of a baby)
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For gel #1 on the biotechnology diagram, which suspect's blood was found at the crime scene? How do you know?
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suspect 2 (banding pattern the same as crime scene sample)
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For gel #2 on the biotechnology diagram, who is the father of the baby? How do you know?
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possible father II (The bands in the baby that could NOT have come from mom are present in father II. Father I does not have all of the bands that the baby has but Mom couldn't have given the kid…therefore it's impossible for this man to be the father)
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For gel #2 on the biotechnology diagram, which numbered band is the largest?
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1 (travelled the shortest distance)
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For gel #2 on the biotechnology diagram, which numbered band is the smallest?
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3 (travelled the farthest)
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Which electrode (positive or negative) will DNA travel towards in gel electrophoresis? Why?
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positive electrode; DNA is negatively charged (think of all of those phosphate groups!). Note that if the electrodes are not labelled in a gel, the side that is labelled is where the wells and negative electrode are found.
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What are the outcomes of the complete sequencing of the human genome?
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knowledge of the number of human genes, location of specific genes, discover of proteins and their functions, study of evolutionary relationships between species, may lead to an understanding of inherited diseases/conditions, may lead to the production of gene probes to detect carriers of genetic diseases, may lead to the production of pharmeceuticals based on DNA sequences, study of human origins/migrations
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What property of the genetic code makes it possible for a gene to be transferred between species?
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The genetic code is universal, so the amino acid sequence of the polypeptides translated from them will be the same.
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Outline the basic technique used for gene transfer.
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mRNA is extracted from the organism with the gene you want use; a DNA copy is made of the RNA using reverse transcriptase; "sticky ends" are added to the DNA copy; the plasmid is cut with restriction enzymes to create sticky ends; the gene (like insulin) and the plasmid DNA are mixed together (the sticky ends will stick together); DNA ligase seals the plasmid together; transformation of the host cell (bacteria, yeast, etc)--putting the recombinant plasmid into the cell; the transformed cells are cultured (grown in good conditions to increase the population size); the host cell will express the gene that was inserted and produce the protein
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What does reverse transcriptase do?
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make DNA from an RNA template; used in gene transfter and by retroviruses (including HIV/AIDS)
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What does DNA ligase do?
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covalently links pieces of DNA; used in gene transfer and DNA replication
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Give 2 examples of genetically modified crops or animals
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IB's examples: salt tolerance gene in tomato plants; sysnthesis of beta-carotene gene in rice; herbicide resistance genes in crop plants; factor IX (human blood clotting gene) in sheep milk. Others may be acceptable.
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What are the potential benefits of genetic modification
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Less expensive food, increased food production, less expensive medicines, etc. See GMO food activity!
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What are the potential harmful effects of genetic modification
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Possibility of allergies in human foods; If genetically engineered organisms are released into the environment they could out-compete naturally occurring varieties, changing the ecosystem; Engineered genes could unintentionally cross from one species to another (transposons); Ethical objections, particularly when human genes/proteins are involved (ie HGH). See GMO food activity...you should be able to give pros and cons for one specific example!
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Define clone
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a group of genetically identical organisms or a group of cells derived from a single parent cell
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Outline a technique for cloning using differentiated animal cells
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remove nucleus from a somatic (non-reproductive) cell from an adult organism; remove nucleus from an egg cell; transfer the nucleus from adult cell into the egg cell; implant the egg with the new nucleus into a host mother; the baby clone will be genetically identical to the adult donor that the nucleus came from. his process is called somatic nuclear transfer.
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What is therapeutic cloning?
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creation of embryos to supply embryonic stem cells for medical use
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What are the ethical issues of therapeutic cloning in humans?
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Pro: 1. Create therapies that save lives and reduce suffering, 2. Cells can be removed from embryos that have stopped developing and would have died anyway 3. Cells are removed at a stage where embryos have no nerve cells and therefore can feel no pain. Con: 1. Every embryo is a potential human being, which should be given the chance of developing. 2. More embryos are produced than are needed, so some may have to be killed. 3. There is a danger of embryonic stem cells developing into tumor cells
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