Bio1151b Chapter 15 The Chromosomal Basis of Inheritance
  1. Mendel's laws of              and independent             can be explained by the             theory of inheritance.
  2. Chromosomes undergo              and independent             during meiosis.
  3. Thomas Hunt Morgan's experiments with fruit flies (             ) showed that the eye-color       is sex-linked and located on the    chromosome.
    • A dihybrid cross with two phenotypes yielded a F1 generation with only the           phenotypes. A            then yielded a F2 generation with all 4 phenotypes.
    • The small number of offspring with              phenotypes implied that the linkage can be broken due to           over and genetic                .
  4. In humans and other mammals, the sex chromosomes    and    determine an organism's gender. X-linked disorders include color blindness,             , Duchenne muscular dystrophy.
  5. Sex-linked disorders exhibit peculiar inheritance patterns.
    • Fathers usually pass a recessive allele to his           as a          .
    • The carrier has a 50% chance of passing the disease to her       .
    • If the carrier marries an affected male,      of the offspring will have the disorder.
  6.                 occurs when homologous chromosomes do not separate normally in meiosis.
  7. In mammalian females, one of the two X chromosomes in each cell is randomly              during embryonic development and can be seen as a compact       body.
  8. A female heterozygous for an X-resident gene may show         phenotype.
  9. Chromosome damage includes           , duplication, inversion, and                .