Genetics Chapter 2

  1. Allele
    An alternative form of a specific gene
  2. Binomial expansion equation
    An equation to solve genetic problems involving two types of unordered events
  3. Character
    a trait
  4. Chi square test
    A commonly used statistical method to determine the goodness of fit. Useful for evaluating the outcome of genetic crosses
  5. Degrees of freedom
    In a statistical analysis, the number of categories that are independent of each other.
  6. Dihybrid testcross
    A cross in which an experimenter crosses and individual that is heterozygous for two genes to an individual that is homozygous recessive for the same two genes.
  7. Dominant
    Describes an allele that determines the phenotype in the heterozygous condition. For example, if a plant is Tt and has a tall phenotype, the tall allele (T)is dominant over the dwarf allele (t).
  8. Eggs
    Also known as an ovum; it is a female gamete that is usually very large and nonmotile.
  9. Empirical approach
    A strategy in which experiments are designed to determine quantitative relationships as a way to derive laws that govern biological, chemical, or physical phenomena.
  10. Empirical Law
    laws that are discovered using an empirical observational approach
  11. Fertilization
    the union of gametes to begin the life of a new organism
  12. cross-fertilization
    same meaning as cross. it requires that the male and female gametes come from separate individuals.
  13. Forked-line method
    a method to solve independent assortment problems in which lines are drawn to connect particular genotypes
  14. Gametes
    a reproductive cell (usually haploid) that can unite with another reproductive cell to create a zygote, sperm and egg cells are types of gametes
  15. F1 Generation
    the offspring produced from a cross of the parental generation
  16. F2 Generation
    the offspring produced from a cross of the F1 generation
  17. Parental (P) generation
    In a genetic cross, the first generation in the experiment. In Mendel's studies, the parental generation was true-breeding with regard to particular traits.
  18. Genotype
    the genetic composition of an individual, especially in terms of the alleles for particular genes
  19. Goodness of fit
    the degree to which the observed data and expected data are similar to each other. If the observed and predicted data are very similar, the goodness of fit is high
  20. Heterozygous
    Describes a diploid individual who has different copies (ie. two different alleles) of the same gene.
  21. Homozygous
    Describes a diploid individual who has two identical alleles of a particular gene.
  22. Hybridization
    1. The mating of two organisms of the same species with different characteristics. 2. The phenomenon in which two single-stranded molecules renature together to form a hybrid molecule.
  23. Hybrids
    A cell produced from the fusion experiment in which the two separate nuclei have fused to make a single nuclei.
  24. Hypothesis testing
    Using statistical tests to determine if the data from experimentation are consistent with a hypothesis.
  25. Law of Independent Assortment
    Two different genes will randomly assort their alleles during gamete formation (if they are not linked).
  26. Law of Segregation
    The two copies of a gene segregate from each other during transmission from parent to offspring.
  27. Loss-of-function alleles
    An allele of a gene that encodes an RNA or protein that is nonfunctional or compromised in function.
  28. Multinomial expansion equation
    an equation to solve genetic problems involving three or more types of unordered events
  29. Multiplication method
    A method to solve independent assortment problems in which the probabilities of the outcome for each gene are multiplied together.
  30. Nonparentals
    in a testcross, refers to a phenotype or arrangement of alleles on a chromosome that is not found in the parental generation.
  31. Ovaries
    • 1. In plants the structure in which the ovules develop.
    • 2. In animals, the structure that produces egg cells and female hormones.
  32. Ovules
    The structure in higher plants where the female gametophyte is produced
  33. P values
    In a chi square table, the probability that the deviations between observed and expected values are due to random chance.
  34. Pangenesis
    an incorrect hypothesis of heredity. it suggested that hereditary traits could be modified depending on the lifestyle of the individual. for example, it was believed that a person who practiced a particular skill would produce offspring that would be better at that skill.
  35. Particulate theory of inheritance
    A theory proposed by Mendel. It states that traits are inherited as discrete units that remain unchanged as they are passed from parent to offspring.
  36. Pedigree Analysis
    A genetic analysis using information contained within family trees. In this approach, the aim is to determine the type of inheritance pattern that a gene follows.
  37. Phenotype
    the observatble traits of an organism
  38. Pollen Grains
    the male gametophyte of flowering plants
  39. product rule
    the probabilty that two or more independent events will occur is equal to the products of their individual probabilities.
  40. Punnett Square
    A diagrammatic method in which the gametes that two parents can produce are aligned next to a square grid as a way to predict the types of offspring the parents will produce and in what proportions
  41. Random Sampling Error
    The deviation between the observed and expected outcomes due to chance.
  42. Segregate
    When two things are kept in separate locations. For example, homologous chromosomes segregate into different gametes.
  43. Single-factor cross
    A cross in which an experimenter is following the oucome of only a single trait.
  44. Sperm
    A male gamete, Sperm are small and usually travel relatively far distances to reach the female gamete.
  45. Stamen
    The structure found in the flower of higher plants that produces the male gametophyte (ie. pollen)
  46. Stigma
    The structure in flowering plants on which the pollen land and the pollen tube starts to grow so that sperm cells can reach the egg.
  47. Strain
    A variety that continues to produce the same characteristic after seceral generations.
  48. Sum rule
    The probability that one of two or more mutually exclusive events will occur is equal to the sum of their individual probabilities.
  49. trait
    any characteristic that an organism displays
  50. True-breeding line
    a strain of a particular species that continues to produce the same trait after several generations of self-fertilization or inbreeding.
  51. Variants
    Individuals of the same species that exhibit different traits. An example is tall and dwarf pea plants.
  52. Dihybrid Cross
    A cross in which an experimenter follows the outcome of two different traits.
Card Set
Genetics Chapter 2
Mendel's Laws of Inheritance