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9 Cards in this Set
- Front
- Back
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what is a gene?
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a specific seqence on DNA in the genome that codes for a protein that has a certain function
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what is PTC and how was it unique taste characteristics discovered?
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PTC is phenylthiocarbamide. The different in people's ability to taste PTC was first discovered by accident. while two researchers were working with PTC one complained about the bitter taste of dust, the other researcher did not believe the dust tasted like anything
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Tasters of PTC are generally a majority in any given population. is this statement true, why or why not?
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Phenylthiocarbamide (PTC) tastes extremely bitter to most people but is tasteless or only slightly bitter to the remainder. The taste insensitivity to PTC is inherited as a Mendelian recessive
The distribution of non tasters for PTC differs from race to race. The percentage of non tasters is 30-40% in European and American Caucasians 5-15% in the Japanese population and 5% in the america indians and Ainus polulations Therefore, true, in caucasians, japanese, and american indian population more than at least 60%of the polation are tasters |
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Tasters of PTC are at higher risk of nicotine addiction than non tasters, is this statement true, why or why not?
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no true
non tasters who are not aversive to the bitter taste of cigarettes may be more at risk of heavy smoking and therefore more vulnerable to nicotine addiction my answer: non tasters are at higher risk base on experiments conducted approx twice as many non tasters compared to the percentage of tasters. heavy smoking has been shown to reduce bitterness taste sensitivity 57%of nontasters are smokers yet 31% of tasters are also smokers |
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PTC tast sensivity is ____ and is best described by a two locus model in which one locus controls PTC tasting and the other controls a more general taste sensitivity
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autosomal dominant
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taster status is somewhat ___ in women than in men
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higher
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given your predispostition toward caffefine and nicotine, do you think you will be a taster or non taster? explain
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I predict i will not be a taster because i have sensed a bitter sensitivity to nicotine in the past
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what evolutionary advantage might the ability to taste PTC confer?
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a selective advantage a defense from us not eating just anything
bitter perception has a particularly important role, as it protects us from ingesting naturally toxic substances which typically taste bitter my answer: to be able to taste toxic compounds and detect them as such to prevent ingesting them |
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what evolutionary advantage might heterozygosity for this trait confer?
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TT & Tt evolutionary advantage
tt why do we have this this , shouldn't it have dropped this shows that there must be an advantage of either Tt or tt If the ability to taste bitter compounds conveys a selective advantage, then shouldn't non-tasters have died off long ago? Why do so many people still carry the non-tasting PTC variant? Some scientists believe that non-tasters of PTC can taste another bitter compound. This scenario would give the greatest selective advantage to heterozygotes, or people who carry one tasting allele and one non-tasting allele. http://learn.genetics.utah.edu/content/begin/traits/ptc/ |
