GeneticsandGeneExpression_SPRING_2011

GeneticsandGeneExpression_SPRING_2011 - February 17, 2011...

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February 17, 2011 “Genetics and Gene Expression”
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Genetics and Gene Expression
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Intelligence Genes Prove Hard to Map Sharon Schmickle Boston Star Tribune BOSTON -- Couples who have dreamed that genetic research might enable them to produce little Einsteins should put that expectation on hold indefinitely , experts said Sunday at a meeting of the American Association for the Advancement of Science. Despite widespread predictions that parents would use new genetic tools to select for smarter children, scientists have not been able to identify genes that would tell whether a child is going to be highly intelligent , said Matthew McGue, a University of Minnesota psychology professor who specializes in IQ studies.
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Some genes that play a role in mental retardation have been isolated , he said. (Should we “fix” these in children in the future? TJJ) But experts in behavioral genetics said researchers are finding the genes that influence overall intelligence and behavior to be more elusive and complex than had been expected a few years ago. Dozens of genes work together to influence intelligence, it now appears, much like an orchestra playing a difficult score. Scientists are giving up on earlier hopes for finding one or two (specific) genes, said Jonathan Beckwith, a professor of microbiology and medical genetics at Harvard Medical School. ………. . The classic yardstick for genetic effects -- comparative studies of twins reared apart and together -- suggests that genetic factors explain about one half of the variation on IQ tests.
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Genetics and Gene Expression In nature, “ natural ” selection has occurred for millions of years – and still happens. But, over the last 10,000 years, people have used artificial ” selection to choose plants and animals for specific purposes. Why don’t closely related people mate or marry? Do you have sexual feelings for your brothers or sisters? (Only due to “conditioning by society?”) Answer: Nature’s way to reduce inbreeding . WHY??? Inbreeding (mating between close relatives) increases chances of diseases and other traits that are linked to recessive genes.
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Inbreeding makes organisms and individuals more homozygous (not as much genetic variability). -- That’s NOT good!! -- Diversity of genes increases the likelihood of survival! How is inbreeding reduced in nature? In animals? Genes are mixed widely among individuals. **Even biological monogamy is the exception in nature! (And, “true” monogamy basically doesn’t exist.) In plants? Many plants are self- infertile . How/why? 1) Male and female parts mature at different times. 2) Chemical incompatibility: -- Female part contains a chemical that prevents the male pollen grain from transferring chromosomes 3) Physical separation on the plant
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Typical flower parts: Fig. 15.16, p. 259 STAMEN (male part) CARPEL (female part) stigma anther filament ovary style Ovule (egg) (forms in the ovary) Anthers are usually above
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GeneticsandGeneExpression_SPRING_2011 - February 17, 2011...

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