Biology-Chapter 14,15,16,17,18

  1. character
    A heritable feature that varies among individuals
  2. Trait
    Each variant for a character
  3. True breeding
    Plants that produce offspring of the same variety when they self pollinate
  4. Hybridization
    Corssing of two true-breeding parents
  5. P generation
    True breeding parents
  6. F1 generation
    Hybrid offspring of P generation
  7. F2 generation
    Offspring of F1 generation
  8. Law of segregation
    • 1. Alternative versions of gene account for variations in inherited characters
    • 2. For each character; an organism inherits two allels, one from each parent
    • 3. If the two allels at a locus differ, then one, the dominate allele, determines the organism's appearance; the other has no noticable affect on the organism's appearance.
    • 4. The two allels for a heritable character segregate during gamete formation and end up in different genes.
  9. allele
    Alternative versions of a gene
  10. Punnett Square
    used to predict allel composition of offspring from a cross between individuals of know genetic make up.
  11. Homozygous
    An organism with a pair of identical allels for a character
  12. Heterozyjous
    An organism taht has two different alleles for a gene
  13. Phenotype
    An organism's observed traits
  14. Genotype
    An organism's genetic make up
  15. Test cross
    Breeding an organism of unknown genotype with a recessive homozygote in order to revel the genotype of an organism.
  16. Monohybrids
    Heterogzygous in one character
  17. Dihybrids
    Heterozygous in two characters
  18. Law of independent assortment
    Each pair of alleles segregates independently of each other pair of alleles during gamete formation. *only applies to genes located on different chromosomes*
  19. Inheritance Deviates from Mendelian Patterns when:
    • -alleles are not completely dominate or recessive
    • -a gene has more than 2 alleles
    • -A single gene produces multiple phenotypes
  20. Incomplete Dominance
    Situation in which the phenotype of herterozygotes is intermediate between the phenotypes of individual's homozyjous of either allele
  21. Codominance
    two alleles both affect the pheontype in separate, distinguishable ways
  22. Tay-sachs disease
    Brain cells cannot metabolize certain lipids and lipids accumulate in the brain.
  23. Pleiotropy
    The ability of a single gene to have multiple effects
  24. Epistasis
    "standing upon", a gene at one locus alters the phenotypic expression of a gene at a second locus
  25. Quantitative characters
    Characters that vary along a continuum. Example-skin pigment varies along a continuum
  26. Polygenic inheritance
    An additive effect of two or more genes on a single phenotypic character
  27. Norm of reaction
    Range of phenotypes produced by a single genotype, due to environment influences. Example-red blood cell count increases at higher elevations
  28. Multifactorial
    Many factors, both genetic and environmental, collectively influence phenotype
  29. Pedigre
    Information about a family's history for a particular trait and assembling this info into a family tree.
  30. Carrier
    Offspring with one recessive allele
  31. Achondroplasia
    A type of dominate trait dwarfism
  32. Huntington's Disease
    Degenerative disease of the nervous system; lethal dominate allele
  33. Amniocentesis
    Needle is inserted into uterus and extracts a 10 mL sample of amniotic fluid
  34. Chronic villus sampling
    Tube is inserted through cervix into uterus and suctions tiny sample of tissue from placenta
  35. Chromosome Theory of Interitance
    Principle stating that genes are located on chromosomes and the behavior of chromosomes during meiosis accounts for inheritance patterns' genes have specific loci along chromosomes and the chromosomes undergo segregation and independent assortment.
  36. Wild type
    Phenotype for a character most commonly observed in natural populations
  37. Mutant phenotypes
    Non wildtypes
  38. Sex-linked genes
    A gene located on either sex chromosome
  39. Duchenne musculardystrophy
    Sex-linked disorder which causes increasing muscle loss caused by a lack of dystrophin
  40. Hemophilia
    Sex-link blood disorder
  41. Barr body
    Inactive X chromosome which condenses and lies along the nuclear envelope of a cell
  42. Inactivation of X chromosome...
    Involves modification of the DNA
  43. Linked genes
    Genes on the same chromosomes that tend to be inherited together in genetic crosses
  44. Genetic recombination
    The production of offspring with combinations of traits that differ from those found in either parent
  45. Parental types
  46. Recombinant types
    Offspring with new genetic combinations
  47. Crossing over
    Reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis
  48. Genetic map
    an ordered list of the genetic loci along a particular chromosome.
  49. Probability of crossing over
    The farther apart two genes are, the higher the probability that a crossover will occur between them and therefore the higher the recombination frequency.
  50. Linkage map
    A genetic map based on recombination frequencies
  51. Map units
    The distance between genes. One map unit is equivalent to 1% recombination frequency
  52. Cytogenetic map
    locates genes with respect to chromosomal features
  53. Nondisjunction
    Members of a pair of homologous chromosomes do not move apart properly during meiosis I or sister chromatids fail to separate during meiosis II
  54. Aneuploidy
    A chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number
  55. Monosomic
    An aneuploid zygote with a missing chromosome
  56. Trisomic
    Three of the same chromosomes are located in a cell
  57. Polyploidy
    Organisms with more than two complete chromosome sets
  58. Chromosomal deletion
    A chromosomal fragment is lost
  59. Chromosomal duplication
    An extra segment on a chromosome
  60. Chromosomal inversion
    A chromosomal fragment attaches in reverse on a chromosome
  61. Chromosomal Translocation
    Chromosome fragment is moved from one chromosome to a nonhomologous chromosome
  62. Genomic imprinting
    Phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent. *caused by methly group that attaches to cytosine nucleotids and silences the allele. Sometimes works in reverse (example: Igf2 allele)
Card Set
Biology-Chapter 14,15,16,17,18