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Gregor Mendel the father of genetics 1822-1884 - studied botany & math - became a monk - studies pea plants and inheritance of traits
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Genetics—the scientific study of heredity Heredity—the passing of traits from parents to offspring
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Why Peas? - many traits that exist in only 2 forms such as Ex: tall vs short plants, no medium - produce a large number of offspring (kids) in each generation - they can self-pollinate or be cross pollinated
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What is self-pollination? pollen from the stamen of a plant enters the pistil of the same plant.
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What is Cross-Pollination? Mendel took pollen from a plant and rubbed it on the pistil of a different plant (with no stamens)
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Cross Pollination diagram
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Purebred —always produces offspring with the same form of a trait as the parent. Ex. Purebred dogs. Like Cocker spaniels, golden retrievers, Poodles. The opposite is hybrid. This would be a pound puppy
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Mendel’s Experiments In his first experiment Mendel crossed purebred tall plants (they only have tall genes) with purebred short plants (that only have short genes). Filial ( F1 ) generation—name given to the offspring of the first cross.
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Mendel’s Experiments ? Mendel cross-pollinated purebred tall plants with purebred short plants and got…. Tall plant (breed) short plants P generation (think “parents”) F 1 generation
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What he found... All TALL pea plants in the F 1 generation…. P generation (think “parents”)F 1 generation
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11 He concluded Tall plants must DOMINATE over short plants He repeated the experiment switching which plant donated the POLLEN Same results He repeated the experiment with several other traits 11
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Traits Mendel studied in Pea Plants Mendel also studied _ 7_ traits of pea plants: They were : Seed shape, seed color, seed coat color, pod shape, flower position, flower color, and stem height.
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Dominant and Recessive Alleles Alleles —the different forms of a gene (such as tall or short, wrinkled or smooth). Dominant allele —one whose trait always shows up when the allele is present. Recessive allele —is masked (or covered up) when the dominant allele is present. Recessive alleles only show up if a dominant allele is not present.
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EXAMPLES recessivedominant Recessive is the green box and dominant is the black box. Each of your parents has a pair of alleles that they can share. If they only give one… answer the following questions. ? ? ? dominant recessive dominant
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EXAMPLES recessivedominant Recessive is the green box and dominant is the black box. Each of your parents has a pair of alleles that they can share. If they only give one… answer the following questions. dominant recessive dominant ? ? ?
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EXAMPLES recessivedominant Recessive is the green box and dominant is the black box. Each of your parents has a pair of alleles that they can share. If they only give one… answer the following questions. dominant recessive dominant ? ? ?
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EXAMPLES recessivedominant Recessive is the green box and dominant is the black box. Each of your parents has a pair of alleles that they can share. If they only give one… answer the following questions. dominant recessive dominant ? ? ? recessive
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Notice The only time the green box (or recessive allele) could show up is when a black box (or dominant allele) was not present. This will lead us into punnett squares. recessive
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Activities for them Pea Soup Animated Cross
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Princess and Wrinkled Pea, BiologicaPrincess and Wrinkled Pea Dragon Genetics, BiologicaDragon Genetics Mendel’s Peas, BiologicaMendel’s Peas Cloning, Brain PopCloning DNA, Brain Pop (digestion, avian flu too)DNA Future activities
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Resources for me Serendipity Labs Holy moly animationsanimations
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