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Cards In This Set
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What is selective breeding?
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It takes advantage of naturally occurring genetic variation in plants, animals, and other organisms, to pass desired traits on to the next generation of organisms
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What does selective breeding allow?
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It allows only those animals with desired characteristics to produce the next generation, humans have produced many different breeds of animals (such as dogs).
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Have nearly all domestic animals and crops been produced by selective breeding?
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Yes
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What did Burbank do?
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He developed the disease-resistant Burbank potato, which was later exported to Ireland to help fight potato blight and other diseases. During his lifetime, he developed more than 800 varieties of plants.
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What is hybridization?
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Crossing dissimiliar individuals to bring together the best of both organisms.
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What organisms are produced by hybridization?
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Hybrids which are generally more strong and health than either of the parents
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Why do breeders use the technique of inbreeding?
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To maintain the desired characteristics of a line of organisms
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What is inbreeding?
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The continued breeding of individuals with similar characteristics
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What type of risks does inbreeding have?
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Because the two organisms breeded are so similar, there is always a chance that a cross between two individuals will bring together two recessive alleles for a genetic defect
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What is the ultimate source of genetic variability?
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Mutations, which is induced by breeders
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What is a mutation?
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Inheritable changes in the DNA
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Mutations occur spontaneously, but breeders can increase the mutation rate by using ____ and _____. These are harmful to the organism.
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Radiation; chemicals
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Why has mutations been particularly useful with bacteria?
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Bacterias small size enables millions of organisms to be treated with radiation or chemicals at the same time. This increases the chance of producing a useful mutant.
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Why are drugs that prevent chromosmoal separation during meiosis particularly useful in plant breeding?
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Sometimes these drugs produce cells that have double or triple the normal number of chromosomes. Plants grown from such cells are called polyploid because they have many sets of chromosomes. Polyploidy is usually fatal in animals but in plants it is much better. Polyploidy may instantly produce new species of plants that are often larger and stronger than thier diploid relatives.
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How are changes made to DNA?
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Scientists use their knowledge of structure of DNA and its chemical properties to study and change DNA molecules. DIfferent techniques are used to extract DNA from cells, to cut DNA into smaller pieces, to identify the sequence of bases in a DNA molecule, and to make unlimited copies of DNA.
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