genetics exam 1

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  1. 2 components of heredity
    • cell to cell (mitosis)
    • organism to offspring (meiosis)
  2. phases of mitosis
    • interphase
    • prophase
    • prmetaphase
    • metaphase
    • annaphase
    • telephase
  3. interphase
    resting phase, build up of organelles
  4. karyokinesis
    equal division of replicated genetic material
  5. cytokinesis
    division of cytoplasm and cell into 2 daughter cells
  6. prophase
    chromatids condense and spindle fibers move to poles
  7. prometaphase
    chromosomes and centromeres completely formed and spindle fibers reach the poles
  8. metaphase
    chromosomes lined up down middle and spindle fibers attach to chromatids of the chromosomes
  9. annaphase
    centromeres divide and chromosomes move apart
  10. telephase
    cell begins to divide (cytoknesis)
  11. meiosis 1
    homologous chromosomes separated to produce haploid daughter cells
  12. meiosis 2
    replication of haploid cells and another division, still haploid
  13. substages of prophase 1
    • leptonema
    • zygonema
    • pachynema
    • diplonema
    • diakinesis
  14. leptonema
    chromosomes condense and search for homolog to pair with
  15. zygonema
    paired chromatids pair with mirror (tetrad) chromosome, bivalent
  16. pachynema
    bivalents are apparent and recombination and/or crossing over occurs
  17. diplonema
    nuclear membrane begins to break down
  18. diakinesis
    chromosomes separate further and chiasma (whats holding them together) begins to fail
  19. mendels 4 laws
    • 1) unit factors occur in pairs- genes occur in pairs
    • 2) dominance/recessive
    • 3) segregation- random gene from sperm/egg
    • 4) independent assortment-genes independent of oneanother
  20. locus
    location of specific gene on a chromosome
  21. incomplete/partial dominance
    RR red flowers rr white flowers Rr pink (blend)
  22. codominance
    blood types A- B- AB O
  23. bombay phenotype
    blood type genetically AB but produces no antigens to enforce, phenotypicaly due to another factor. They can donate like were O type but can only receive another bombay's blood.
  24. 2 lethal alleles
    1) Recessive lethal- death from homozygous recessive and unique charachteristic from heterozygous 

    2) Dominant lethal- heterzygous dominant still born, heterzygous delayed onset (later in life)
  25. epistatic
    gene being expressed
  26. hypostatic
    gene altered or suppressed
  27. epistasis (epistatic vs hypostastic)
    • epistatic is being expressed while hypostatic is being altered or suppressed and loci are not linked. and each combo has its own phenyotype.
    • 9:3:3:1
  28. dominant epistasis
    • if A is present over anything then its that, if B is present then that unless A, if recessive and neither A or B then that.
    • 12:3:1
  29. recessive epistatis
    • A- needs B- to make full color, A-bb makes a different color, anything with aa is masked (albino)
    • 9:3:4
  30. duplicate recessive epistasis
    • both genes are A- and B- then you get result, if one or more are homo recessive then absent
    • 9:7
  31. complemantation analysis and alleles
    • test to see if two similiar/same phenotypes come from same gene.
    • case 1- they form heterozygous of two genes and phenotype is as normal

    case 2- produces original/mutant phenotype
  32. hemizygous
    male who has one X chromosome and other Y
  33. sex limited inheritance
    expression of phenotype is limited to a specific gene (men having beards)
  34. linkage
    genes located proximal on cromatid will most likely cross over together.
  35. sex influenced
    one sex exhibits a more pronounced phenotype than other sex (balding male vs female thinning)
  36. penetrance
    % individuals  carrying a genotype who show at least some expression
  37. expressivity
    range of expression of phenotype
  38. 2 components involved in variable expressivity
    • internal- genetic background (epistatic factors)
    • external- temp, hymidity, nutrition
  39. extra-chromosomal inheritance
    • modify Mendelian patterns by:
    • 1)some organelles have own DNA
    • 2)mother gives X chromsome already acting on egg before its born
  40. heteroplasmy
    mixed population of mutant and normal. gene being picked while mother goes through meiosis and how it effects egg development.
  41. dioecious/gonochoris
    distinct males and females
  42. monoecious
  43. isogametes and isogamous
    as condition decrease organism that produces monoeciously goes dioecious and with two gametes form
  44. how many human chromosomes?
  45. klinefelters syndrome
    (47, XXY) usually sterile enlarged breasts, 2/1000
  46. turners syndrome
    (45, XO) external genitalia, underdeveloped ovaries 1/3000
  47. nondisjunction
    failure of sex chromosomes to divide in either meiosis 1 or 2
  48. XXX syndrome
    (47, XXX) under developed 2nd sex characteristics, possible retardation 1/2000
  49. XYY syndrome
    (47, XYY) above average height, antisocial, possible lower intelligence. 1/1000
  50. primary sexual differentiation
    involves only the gonads where gametes are produced
  51. secondary sexual differentiation
    overall appearance of organism
  52. Maize diploid plant
    goes through self fertilizing stage and sporophyte stage
  53. 3 Y chromosome regions
    • pseudoautosomal region (PAR)
    • male specific region of Y (MSY)
    • sex determining region Y (SRY)
  54. pseudeautosomal region (PAR)
    allow Y to pair with homolog X
  55. male specific region of Y (MSY)
    a lot of male genetic info
  56. sex determining region y (SRY)
    encodes a product that triggers testes to form
  57. euchromatin vs heterochromatin
    euchromatin is actively being used and loosely packed

    heterochromatin has two stages but not expressed
  58. euchromatin
    unpacked DNA with active genes
  59. 2 types of heterochromatin
    • facultative- inactive euchromatin that are condensed
    • constitutive- devoid of gene and inactive, structural support
  60. Barr bodies
    inactivates one of 2 X chromosomes so over expression does not happen
  61. lyons hypothesis
    one X chromosome gives one feature while other X chromosome gives another and both show. calico cats, one x codes for two colors other white.
  62. sex determination in flies
    determined by number of X chromosomes (females can have a Y)
  63. aneuploidy
    1 or more individual chromosomes are added or deleted
  64. euploidy
    having multiples of entire genome
  65. temp dependent sex determination
    enzyme is activated at specific temp range, 3 types
  66. monosomy
    loss of one of two homologs
  67. disomy
    normal set of chromosomes
  68. partial monosmy
    part of chromosome is deleted
  69. trisomy
    3 copies of chromosome
  70. down syndrome
    (47 21+) trisomy of #21 chromosomes
  71. patau syndrome
    (47, 13+) large chromosome, many side effects
  72. edward syndrome
    (47, 18+) heart defects, kidney defects. 80% affected are female. majority die before birth.
Card Set:
genetics exam 1
2013-09-19 04:29:53

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