Module 8

  1. True Breeding
    If an organism has a cerain characteristic that is always passed on to all of its offspring, we say that this organism bred true with respect to that chatacteristic.
  2. Allele
    One of a pair of genes that occupies the same position on homologous chromosomes.
  3. Genotype
    Two-letter set that represents the allels an orgamism possesses for a certain trait.
  4. Phenotype
    The observable expression of an organism's genes.
  5. Homozygous Genotype
    A genotype in which both alleles are indentical.
  6. Heterozygous Genotype
    A genotype with two different alleles.
  7. Dominant Allele
    An allele that will determine phenotype if even one is present in the genotype.
  8. Recessive Allele
    An allele that will not determine the phenotype unless the genotype is homozygous with that allele.
  9. Mendel's Principles Of Genetics (Use Updated Terminology)
    • 1. The traits of an organism are determined by its genes.
    • 2. Each organism has two alleles that make up the genotype of a given trait.
    • 3. In sexual reproduction, each parent contributes ONLY ONE of its alleles to the offspring.
    • 4. In each genotype, there is a dominant allele. If it exists in an organism, the phenotype is determined by that allele.
  10. Pedigree
    A diagram that follows a particular species' phenotype through several generations.
  11. Monohybrid cross
    A cross between two individuals concentrating on only one definable trait.
  12. Dihybrid cross
    A cross between two individuals concentrating on two definable traits
  13. Autosomes
    Chromosomes that do not determine the sex of an individual
  14. Sex chromosomes
    Chromosomes that determine the sex of an individuals
  15. Autosomal inheritance
    Inheritance of a genetic trait not on a sex chromosomes
  16. Genetic disease carrier
    A person who is heterozygous in a recessive genetic disorder
  17. Sex-linked inheritance
    Inheritance of a genetic trait located on the sex chromosomes
  18. Mutation
    A radical chemical change in one or more alleles
  19. Change in chromosome structure
    A situation in which the chromosomes loses or gains genes during meiosis
  20. Change in chromosome number
    A situation in which abnormal cellular events in meiosis lead to eather none of a particular chromosome in in the gamete or more than one chromosome in the gamete
Card Set
Module 8