Biology 40s Exam - Genetics

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Biology 40s Exam - Genetics
2015-01-26 12:36:03

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  1. purpose of mitosis
    the process to duplicate body cells into two genetically identical daughter cells
  2. purpose of meiosis
    the process to create sex cells or gametes that only have one sit of chromosomes
  3. process of mitosis
    cell duplication/replication
  4. process of meiosis
    reduction division
  5. number of divisions in mitosis
  6. number of divisions in meiosis
  7. product of mitosis
    1 cell -> 2 daughter cells
  8. product of meiosis
    1 cell -> 4 cells (gametes)
  9. define allele
    • alternate forms of a particular gene
    • the alleles for a trait occupy the same position
  10. define dominant
    the dominant allele will always be expressed
  11. define recessive
    • versions of genes that are less influential
    • for a recessive trait to show, one must have two recessive alleles for a specific trait
  12. define genotype
    the gene that an organism has for a specific trait
  13. define phenotype
    the observable or expressed traits of an organism
  14. define complete dominance
    if two alleles display complete dominance, it is not possible to tell the difference between the homozygous dominant individual and the heterozygous individual
  15. define homozygous
    having two identical alleles for a given trait
  16. define heterzygous
    having two different alleles for a given trait
  17. define hybrid
    the same as heterzygous
  18. define pure-breeding
    homozygous dominant
  19. define gamete
    sex cells
  20. define F1/F2 generations
    filial = offspring
  21. define chromosomes
    • a structure in the cell nucleus that contains dna
    • a single piece of dna contains many genes
  22. define homologous chromosomes
    • the same size, same shape, and have the same gene map
    • not necessarily genetically identical
  23. define sister chromatids
    identical copies of chromosome connected by a centromere 
  24. define crossing over
    process where two chromosomes pair up and exchange sections of dna
  25. define diploid
    • contains two sets of chromosomes
    • one set from each parent
  26. define haploid
    • contains one set of chromosomes 
    • gametes
  27. define cytokinesis
    • division of cytoplasm after chromosomes separate
    • in plants, new cell wall forms
    • in animals, cleavage furrow forms to divide cell
  28. stages of mitosis
    • prophase
    • metaphase
    • anaphase
    • telophase
  29. define mendelian genetics
    • mendel experimented with plant heredity by controlling the pollination
    • mendel determined that certain factors controlled the characteristics of the plants
    • these are genes, he concluded that some are dominant and others are recessive
  30. what are mendels laws of heredity
    • law of segregation
    • law of independent assortment
  31. define law of segregation
    each organism has 2 alleles for each trait which separate and only one allele passes to the offspring
  32. define law of independent assortment
    each pair of alleles segregates independently of other pairs so that all possible combinations of alleles can occur in gametes
  33. define monohybrid crosses
    cross between two heterozygous or hybrid parents
  34. define punnett squares
    a diagram that shows every possible combination of alleles 
  35. define test cross
    • when the genotype is unknown but the individual displays dominant phenotype
    • cross with an individual known to have a homozygous recessive genotype 
  36. define dyhybrid crosses
    two heterozygous indiviuals for 2 traits are crossed 
  37. what is the rule for two heterozygous parents for two traits 
    9 3 3 1 rule
  38. what are the exceptions to mendel's principles
    • incomplete dominance
    • co-dominance
    • pleiotropy
    • epistasis
    • polygenic traits
    • lethal genes
    • multiple alleles
  39. define incomplete dominance
    • the heterozygous condition expresses both alleles for a specific trait
    • results in a combined phenotype
  40. define co-dominance
    two dominant alleles are expressed at the same time without the blending of traits
  41. define pleiotropy
    a single gene can affect another characteristic/phentoype
  42. define epistasis
    one gene may interfere with the expression of another gene that is independently inherited
  43. define polygenic traits
    traits that are controlled by more than one pair of alleles
  44. define lethal genes
    • a mutant form of a gene that results in death if expressed in the phenotype
    • can be either dominant or recessive, most are recessive
  45. define multiple alleles
    having 3 or more alleles that affect a particular trait
  46. define antigens
    proteins on the membranes of ever red blood cell
  47. define antibodies
    • in the blood plasma
    • formed in response to the presence of antigens
  48. what are the blood types with their antigens and antibodies
    • type A: has antigen-A, anti-B antibodies
    • type B: has antigen-B, anti-A antibodies
    • type AB: has antigen-A & antigen B, no antibodies
    • type O: no antigens, anti-A & anti-B antibodies
  49. what are the genotypes for each blood type
    • type A: IAIA or IAi
    • type B: IBIB or IBi
    • type AB: IAIA
    • type O: ii
  50. define sex-linked inheritance
    • alleles on sex chromosomes are inherited in predictable patterns
    • female - XX (homozygous)
    • male - XY (heterozygous)
  51. what are sex-linked traits
    • involve the gene being on the x-chromosome
    • women who have XX have protection of becoming heterozygous, males don't
    • males have 1 x-chromosome, they will show the phenotype if they receive the recessive allele
  52. what are the different ways a trait is passed on 
    • autosomal dominant
    • autosomal recessive
    • sex-linked dominant
    • sex-linked recessive
    • mitochondrial inheritance
  53. define autosomal dominant
    • every generation
    • family members don't transmit the phenotype
    • males and females equally affected
  54. define autosomal recessive
    • skips generations
    • may transmit phenotype
    • males and females equally affected
  55. define sex-linked dominant
    • every generation
    • males pass on to daughters
    • females more than males
  56. define sex-linked recessive
    • skips generation
    • daughters may be carriers
    • males don't pass on to sons
  57. define mitochondrial inheritance
    • inherited from the mother
    • mothers are carriers
  58. define chromosome mutations
    • monosomy: aneuploidic condition where you have a single copy of a chromosome
    • aneuploidy: variation in chromosome number; the gain or loss of a singl chromosome
  59. what are the syndromes
    • turner syndrome
    • cri du chat syndrome
    • trisomy
    • patau syndrome
    • edwards syndrome
    • down syndrome
    • klinefelter's syndrome
  60. define turner syndrome
    women have only one x chromosome
  61. define cri du chat syndrome
    • mew-like cry of affected children due to a malformation of the larynx 
    • caused by missing arm of chromosome 5
  62. define trisomy
    an abnormal aneuploidic condition where there are three copies instead of two
  63. define patau syndrome
    the embryos that do survive to birth, common abnormalities include - mental & motor challenged
  64. define edwards syndrome
    heart abnormalities, kid malformations, and other internal organ disorders
  65. define klinefelter's syndrome
    a condition where males have an extra x sex chromosome. xxy
  66. define intersexuality
    • biological characteristics of both the male and female sexes
    • true hermaphrodite =xxxy
  67. define heredity
    the passing on of physical or mental characteristics genetically from one generation to another