Chapter 6: Introduction to Genetics Section 6-1: The Science of Inheritance and Gregor Mendel

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Text of Chapter 6: Introduction to Genetics Section 6-1: The Science of Inheritance and Gregor Mendel

  • Chapter 6:Introduction to GeneticsSection 6-1:The Science of Inheritance and Gregor Mendel

  • Parents and OffspringHeredity = biological inheritanceAn organisms heredity is the set of characteristics it receives from its parents.Genetics is the study of heredity.Heredity IS NOT just a blend of characteristics from both parents look at page 124

  • Gregor MendelBorn in 1822, became a monk, but also studied science and math in Vienna

    In the monastery, Mendels job was to take care of the garden (monasteries are self-sustaining)

    He took an interest in pea plants he began with true-breeding stock

  • True-Breeding StockTrue-breeding stock refers to individuals that always pass on their characteristics to the next generation (ex. a tall pea plant with green pods will ALWAYS produce tall pea plants with green pods)

  • Reproduction in Pea PlantsPeas use their flowers to reproduce (p.125)Male sex cell = pollenFemale sex cell = eggPea plants normally self-pollinate, meaning the pollen and egg come from the same plant (basically only one parent)True-breeding stock results from generations of self-pollination

  • Mendel and Pea PlantsMendel wanted to see what would happen if he crossed true-breeding stock with different characteristicsMendel removed all the male plant parts so that he could control pollination, making sure that pollen and egg came from different plantsThis is called cross-pollination

  • Mendels Seven TraitsTrait = characteristic that identifies one individual from another

    Mendel focused on seven traits, each with two contrasting forms

  • Mendels Seven Traits

  • Mendels Seven TraitsMendel used true-breeding stock to create hybrids offspring of parents with different characteristicsThe hybrids were called the first filial generation (F1 generation) and the true-breeding stock were called the parental generation (P generation)

  • Mendels Seven TraitsMendel noticed the traits seen in the F1 generation were not a blending of the P generations traits

    The traits of only ONE parent appeared in the offspring while the traits of the other parent seemed to disappear