Bio1151b Chapter 14 Mendel and the Gene Idea
  1. Gregor Mendel experimented with peas,
  2. When Mendel mated two true-breeding varieties (the    generation), all of the offspring (the     generation) from this             cross had         flowers.
  3. Mendel proposed two principles of inheritance to explain his results.
  4. Law of              .
    • "Heritable factors" (genes) have alternative versions called          .
    • If the two alleles at a locus differ, the organism is               , and the           allele determines the organism's appearance, or            .
    • The two alleles            in meiosis, and rhe distribution of the segregated phenotypes can be calculated from a              model called the          square.
    • How can we determine the genotype of an organism with the dominant            ? A testcross with an individual that is homozygous            for the trait.
  5. Law of Independent             .
    • Crossing true-breeding parents differing in two characters produces            in the F1 generation heterozygous for both characters, and       phenotypes in the F2 generation.
    • Each pair of alleles segregates                and randomly during gamete formation, assuming they are on different              ,
  6. Mendel's laws are based on probability, and obey rules of                 and           .
    • In a             cross, the probability of allele frequencies in the         is the          of the probabilities of allele frequencies in the          .
    • In a              cross, the probabilities of multiple allele combinations is the      of the probabilities of the individual alleles.
  7. Extending Mendelian Genetics.
    • In           dominance, the             of the heterozygote and dominant homozygote are identical.
    • In             dominance, the            of                is somewhere between the phenotypes of homozygotes. An example is the flower color of snapdragons.
    • In              , two dominant alleles affect the phenotype. An example is the human blood group ABO, where phenotypes are determined by           alleles.
    • Some traits exhibit            inheritance which oftens shows               variation.
    • In            , a gene at one        may alter the phenotypic expression of a gene at a second locus. An example is the mouse coat color.
  8. Inheritance in human families can be studied by analyzing a           showing the inheritance of alleles across generations.