Biology test 5

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  1. What are characters in genetics?
    Different heritable features, such as flower color
  2. What are traits in genetics?
    Character variants, such as purple or white flower color
  3. What are the advantages of using the pea plants in genetic study?
    • Characters and character traits
    • Mating easily controlled
    • Stamens and carpel
    • Cross pollination (fertilization between different plants) involves dusting one plant with the pollen of another
  4. What are the sperm and egg producing organs in plants?
    • Stamens
    • Carpel
  5. True-breeding
    Plants that produce offspring of the same variety when they self-pollinate
  6. Hybridization
    Mating 2 contrasting, true-breeding varieties
  7. True breeding parents
    P generation
  8. F1 generation
    The offspring of the true breeding parents
  9. F2 generation
    The product of when the Fgeneration self-pollinates or cross pollinates with another Fhybrid
  10. What was Mendel's term for genes?
    Heritable factors
  11. What were some of Mendel's important discoveries?
    • Factors exist in versions (alleles)
    • Alleles segregate/separate (law of segregation)
    • Independent assortment
    • Particulate inheritance
  12. What 3 mechanisms contribute to genetic variation?
    • Independent assortment of chromosomes
    • Crossing over
    • Random fertilization
  13. What factors should an experimental organism have?
    • Easy to culture (small size; minimal nutrient requirements)
    • Quick generation time
    • Simple genetics
    • Mutant form apparent
    • Economic importance
  14. Character state
    Discreet expression or form, 1 among several, for a given character.
  15. Monohybrid
    Individuals that are heterozygous for one character
  16. Dihybrids
    Heterozygous for both traits
  17. Law of Segregation
    the two alleles for a heritable character separate (segregate) during gamete formation and end up in different gametes
  18. Law of Independent Assortment
    • •each pair of alleles segregates
    • independently of each other pair of alleles during gamete formation
  19. Inheritance of characters by a single gene may deviate from simple Mendelian patterns in certain situations such as
    • When alleles are not completely dominant or recessive 
    • More than one allele
    • When a gene produces multiple phenotypes
  20. Complete dominance
    occurs when phenotypes of the heterozygote and dominant homozygote are identical
  21. Incomplete dominance
    the phenotype of F1 hybrids is somewhere between the phenotypes of the two parental varieties
  22. Codominance
    two dominant alleles affect the phenotype in separate, distinguishable ways
  23. Polygenic inheritance
    an additive effect of two or more genes on a single phenotype
  24. Chromosome Theory of Inheritance
    –Mendelian genes have specific loci (positions) on chromosomes

    –Chromosomes undergo segregation and independent assortment
  25. Wild type phenotype
    the most commonly occurring phenotype in nature
  26. How do you create an Fgeneration?
    Cross the Fgeneration with itself
  27. Types of linkages
    • Two traits on same chromosome
    • sex-linkage: a trait that is linked on a sex chromosome
  28. What is the SRY gene's function?
    On Y chromosomes, code for male anatomical parts
  29. For a recessive X-linked trait to be expressed...
    • Female needs two copies of the alleles (heterozygous)
    • Male needs one copy of the alleles (hemizygous)
  30. Parental types
    offspring with same phenotypical traits as the parents
  31. Recombinant
    Offspring with phenotypical traits different from parents
  32. Semi-conservative
    Some of the DNA that is replicated is the old strand and some is new
  33. Topoisomerase
    Enzyme that prevents supercoiling by cutting DNA and then reconnecting it
  34. DNA helicase
    Unwinds DNA
  35. Single stranded binding proteins (SSBP)
    Protects DNA while in single stranded state
  36. Okazaki fragments
    Each fragment on a lagging strand
  37. Coding DNA
    Used to make proteins
  38. Origins of replication
    Where the two DNA strands are separated, opening a replication bubble
  39. RNA primase
    An enzyme that starts an RNA chain from scratch and adds RNA nucleotides one at a time using the parental DNA template
  40. DNA ligase
    Joins together Okazaki fragments
  41. Codon
    mRNA base triplet
  42. Transcription unit
    Stretch of DNA that is transcribed
  43. Three stages of transcription
    • Initiation
    • Elongation
    • Termination
  44. Anticodon
    Carried by tRNA. Base pairs with a complementary codon on mRNA
  45. Replication fork
    Y shaped region where new DNA strands are elongating
  46. DNA polymerase
    synthesizes a leading strand continuously, moving toward the replication fork
  47. RNA primer
    Short nucleotide strand where the 3' end serves as the starting point for a new DNA strand
  48. Gene expression
    The process by which DNA directs protein synthesis in transcription and translation
  49. Transcription
    The synthesis of RNA under the direction of DNA
  50. Translation
    Synthesis of polypeptide using information in the mRNA
  51. Site of translation
  52. Primary transcript
    The initial RNA transcript from any gene prior to processing
  53. Central dogma
    • Concept that cells are governed by a cellular chain of command:
    • DNA -> RNA -> protein
  54. Template strand
    One of the two DNA strands that provides a template for ordering the sequence of complementary nucleotides in a RNA transcript
  55. RNA polymerase
    Pries the DNA strands apart and hooks together the RNA nucleotides
  56. Promoter
    The DNA sequence where the RNA polymerase attaches
  57. Terminator
    Sequence signaling the end of transcription
  58. RNA processing
    When enzymes in the eukaryotic nucleus modify pre-mRNA before the genetic messages are dispatched to the cytoplasm
  59. During RNA processing, has is pre-mRNA modified?
    The 5' end gets 5' cap and the 3' end gets a poly-A tail
  60. What are the functions of the 5' cap and the poly-A tail?
    • Facilitate the export of mRNA
    • Protect mRNA from hydrolytic enzymes
    • Help ribosomes attach to 5' end
  61. Introns
    Non-coding sequences in RNA
  62. Exons
    Regions that are eventually expressed and translated into amino acid sequences
  63. RNA splicing
    Removes introns and joins exons
  64. Spliceosomes
    Consist of a variety of proteins and several small ribonucleoproteins (snRNPs) that recognize splice sites
  65. What are the three binding sites for tRNA on a ribosome and what are their functions?
    • P site: holds the tRNA that carries the growing polypeptide chain
    • A site: holds the tRNA that carries the next amino acid to be added to the chain
    • E site: exit site where discharged tRNAs leave the ribosome
  66. Nucleotide pair substitution
    Replaces one nucleotide and its partner with another pair of nucleotides
  67. Silent mutations
    Have no effect on the amino acid produced by a codon because of redundancy in the genetic code
  68. Missense mutations
    Still code for an amino acid, but not the correct amino acide
  69. Nonsense mutations
    Change an amino acid codon into a stop codon nearly always leading to a nonfunctional protein
  70. Insertion or deletion of nucleotides may alter the reading frame, producing a...
    Frameshift mutation
  71. Mutagens
    Physical or chemical agents that can cause mutations
  72. When did Darwin publish Origin of Species?
  73. Scala natura
    Scale on which organisms were arranged by Aristotle when they were thought to be static
  74. Catastrophism
    Organisms are molded by catastrophe
  75. Uniformitarianism
    Mechanisms of change are constant over time, such as weathering/erosion, sedimentation, subsidence/uplift
  76. Homology
    Similarity coming from common ancestry
  77. Homologous structures
    Anatomical resemblances that represent variations on a structural theme present in a common ancestor
  78. Vestigial structures
    Remnants of features that served important functions in the organism's ancestors
  79. Biogeography
    Geographic distribution of species
  80. Endemic species
    Species that are not found anywhere else in the world
  81. Convergent evolution
    Evolution of similar or analogous features in distantly related groups
  82. Logistic/Sigmoid growth
    When a species does not take the carrying capacity of its habitat into consideration so therefore produces too many offspring which then die rapidly, creating a sharp incline and decline in population
  83. Intrinsic rate of growth
    R max
  84. Types of fossils
    • Direct (bones, tissue)
    • Indirect (footprints, dung, teeth marks)
    • Micro and macro (unicellular organisms)
  85. Aspects of Natural Selection
    • Variation in a population
    • Phenotype/physical differences associated with differences in reproductive success (fitness)
    • Populations always grow beyond the environment's capacity to support them
    • Competition ensues
    • Differential reproduction and survival of so-called "favored" variation
Card Set
Biology test 5
Mendelian Genetics through Transcription and translation
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