Bio final

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Bio final
2011-12-09 11:32:55
Biology science

Ch 1 -18
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  1. Which series of terms is in the correct sequence of biological organization, from the simplest to the most complex?

    a) tissue, organ system, organ, cell, organism
    b) organisim, ecosystem, community, population, biosphere,
    c)cell, tissue, organ, population, community
    C is the correct answer
  2. In an experimental procedure, repititiom of the procedures are necessary because________.
    is necessary before concluding that a given set of results is correct
  3. How is the information encoded in DNA actually used by organisms?
    the information in DNA is transcribed to RNA and then translated into protein
  4. Experimentation is only one part of the process of scientific inquiry, but it is a very important step because it _________.
    allow rejection of a hypotheses when contradictory evidence emerges
  5. Which of the following best demonstrates the unity among all organisms?
    the structure and function of DNA
  6. Which kingdom in the domain Eukarya is composed of organism that are generally unicellular?
  7. Name and describe all the kingdoms of Domain Eukarya.
    Kingdom Plantae- terrestrial multicellular eukaryotes that carry out photosynthesis

    Kingdom fungi- eukaryotes that derive nutrients from the outside of their body.

    Protist- unicellular eukaryotes and some relatively small multicellular relatives

    Kingdom animialia- multicellular organism that digest other organisms
  8. Pathway similarities suggest that ancestral signaling molecules evolved in ______and were modified later in eukaryote
  9. true or false. The concentration of signaling molecules with enviromental conditions allows bacteria to sense local population density
    false. conditions have no effect; only concentration of signaling molecules ables qoutem sensing
  10. define local regulators
    messenger molecules that travel only short distances
  11. true or false. A cell can respond to a signal without receptors
    false. The ability of a cell to respond to a signal depends on whether or not it has a receptor specific to that signal
  12. describe Earl W. Sutherland's experiment with epinephrine
    discovered how epinephrine acts on cells, suggesting that cells receiving signals went through three processes
  13. what is another name for protein receptor
  14. A shape change in a receptor is often the initial transduction of the signal
  15. Most ______ bind to specific sites on receptor proteins that span the plasma membrane
    water-soluble signal molecules
  16. name the three main types of membrane receptors
    • – G protein-coupled receptors
    • – Receptor tyrosine kinases
    • – Ion channel receptors
  17. give three characteristics of G protein-coupled receptors (GPCRs)
    • • the largest family of cell-surface receptors
    • • A GPCR is a plasma membrane receptor that works with the help of a G protein
    • • The G protein acts as anon/off switch: If GDP isbound to the G protein, the G protein is inactiv
  18. give three characteristics of Receptor tyrosine kinases (RTKs)
    • • Receptor tyrosine kinases (RTKs) are membrane receptors that attach phosphates to tyrosines
    • • A receptor tyrosine kinase can trigger multiple signal transduction pathways at once
    • • Abnormal functioning of RTKs is associated with many types of cancer
  19. give two characteristics of ligand-gated ion channe
    • • A ligand-gated ion channel receptor acts as a gate when the receptor changes shape
    • • When a signal molecule binds as a ligand to the receptor, the gate allows specific ions, such as Na+or Ca2+, through a channel in the recepto
  20. are Intracellular receptor proteins found in the cytosol or nucleus of target cell?
  21. true or false. Small or hydrophobic chemical messengers can readily cross the membrane and activate receptor
  22. give examples of hydrophobic chemical messenger
    Examples of hydrophobic messengers are the steroid and thyroid hormones of animal
  23. can An activated hormone-receptor complex act as a transcription factor, turning on specific gene?
  24. what are the benefits of multiple pathways in signal transduction?
    • • Multistep pathways can amplify a signal: A few molecules can produce a large cellular response
    • • Multistep pathways provide more opportunities for coordination and regulation of the cellular respons
  25. true or false. The molecules that relay a signal from receptor to response are mostly lipids
    false. proteins are the molecules most of the time
  26. Like falling dominoes, the receptor activates another protein, which activates another, and so on, until the protein producing the response is activate
  27. • In many pathways, the signal is transmitted by a cascade of protein phosphorylation
  28. Protein kinase
    transfer phosphates from ATP to protein, a process called phosphorylation
  29. Protein phosphatases
    remove the phosphates from proteins, a process called dephosphorylation
  30. The ________ is a pathway’s “first messenger
    extracellular signal molecule (ligand) that binds to the receptor
  31. Second messengers
    small, nonprotein, watersoluble molecules or ions that spread throughout a cell by diffusion
  32. Second messengers participate in pathways ______.
    initiated by GPCRs and RTK
  33. name two common second messengers
    Cyclic AMP and calcium ions
  34. Adenylyl cyclas
    an enzyme in the plasma membrane, converts ATP to cAMP in response to an extracellular signal
  35. cAMP usually activates_______ , which phosphorylates various other protein
    protein kinase A
  36. Further regulation of cell metabolism is provided by _______ that inhibit adenylyl cyclase
    G-protein systems
  37. why are calcium ions important second messengers?
    Calcium is an important second messenger because cells can regulate its concentration
  38. Pathways leading to the release of calcium involve____________as additional second messengers
    inositol triphosphate (IP3) and diacylglycerol (DAG)
  39. trueor false. At each step of signal amplification, the number of activated products is much greater than in the preceding steps
  40. true or false. Inactivation mechanisms are an essential aspect of cell signaling
  41. Apoptosis
    programmed or controlled cell suicide
  42. how are cells undergo apotosis not take up space?
    Components of the cell are chopped up and packaged into vesicles that are digested by scavenger cells
  43. what is a benefit of apoptosis besides recycling useless cells?
    Apoptosis prevents enzymes from leaking out of a dying cell and damaging neighboring cells
  44. _____________ are the main proteases (enzymes that cut up proteins) that carry out apoptosis
  45. name three triggers of apoptosis
    • – An extracellular death-signaling ligand
    • – DNA damage in the nucleus
    • – Protein misfolding in the endoplasmic reticulu
  46. Apoptosis may be involved in some diseases (for example, ______’s);
    Parkinson’s, cancer, and Alzheimer
  47. true or false. Prokaryotes and eukaryotes alter gene expression in response to their changing environmen
  48. In multicellular eukaryotes, gene expression __________
    regulates development and is responsible for differences in cell types
  49. RNA molecules play many roles in _______
    regulating gene expression in eukaryote
  50. Gene expression orchestrates _________
    the developmental programs of animal
  51. The transformation from zygote to adult results from :
    cell division, cell differentiation, and morphogenesis
  52. Cell differentiation
    the process by which cells become specialized in structure and function
  53. morphogenesis
    The physical processes that give an organism its shape constitute
  54. ________ results from genes being regulated differently in each cell type
    Differential gene expression
  55. true or false An egg’s cytoplasm contains RNA, proteins, and other substances that are distributed evenly in the unfertilized egg
    false. unevenly
  56. Cytoplasmic determinante
    maternal substances in the egg that influence early development
  57. true or false. As the zygote divides by mitosis, cells contain different cytoplasmic determinants, which lead to different gene expression
  58. The other important source of developmental information is the environment around the cell, especially signals from nearby embryonic cells
  59. induction
    signal molecules from embryonic cells cause transcriptional changes in nearby target cells
  60. true or false. interactions between cells during embryonic develepoment induce differentiation of specialized cell type
  61. Determination
    commits a cell to its final fate
  62. Cell differentiation is marked by ______
    the production of tissue-specific protein
  63. function of Myoblast
    produce muscle-specific proteins and form skeletal muscle cells
  64. name and describe MyoD
    • one of several “master regulatory genes” that produce proteins that commit the cell to becoming skeletal muscle
    • • The MyoD protein is a transcription factor that binds to enhancers of various target gene
  65. Pattern formation
    • the development of a spatial organization of tissues and organs
    • • In animals, pattern formation begins with the establishment of the major axe
  66. Positional information
    the molecular cues that control pattern formation, tells a cell its location relative to the body axes and to neighboring cell
  67. Pattern formation has been extensively studied in the fruit fly _________
    Drosophila melanogaster
  68. true or false. In Drosophila and humans, cytoplasmic determinants in the unfertilized egg determine the axes before fertilization
    false. not in humans
  69. homeotic genes
    control pattern formation in late embryo, larva, and adult stages
  70. embryonic lethals
    causing death during embryogenesi
  71. Maternal effect gene
    encode for cytoplasmic determinants that initially establish the axes of the body of Drosophila
  72. eggpolarity genes
    they control orientation of the egg and consequently the fly
  73. Ribozymes
    catalytic RNA molecules that function as enzymes and can splice RNA
  74. Spliceosomes
    consist of a variety of proteins and several small nuclear ribonucleoproteins(snRNPs) that recognize the splice sites
  75. RNA splicing
    removes introns and joins exons, creating an mRNA molecule with a continuous coding sequence
  76. exon
    noncoding regions eventually expressed, usually translated into amino acid sequence
  77. introns
    These noncoding regions are called intervening sequence
  78. A cell translates an mRNA message into protein with the help of_____
    transfer RNA (tRNA)
  79. tRNAs transfer ______
    amino acids to the growing polypeptide in a ribosom
  80. • The three stages of translation
    • – Initiation
    • – Elongation
    • – Termination
  81. true or false.only two stages require protein “factors” that aid in the translation proces
    false. all tree
  82. What is the terminology for unequal separation of chromosomes
  83. What is the alternation of chromosome structure called when the reverse orientation of a chromosome occurs within a segment
  84. What is the only viable monosomy in humans? (Hint: these patients are sterile and always female)
    turner's syndrome; XO
  85. True or False: A centimorgan, known as a map unit, represents 1% recombination frequency
  86. What is the enzyme that “unzips” double stranded DNA during replication
  87. What is the term for highly condensed DNA and proteins that will not be involved in transcription or replication
  88. DNA is synthesized in what direction
    5' to 3'
  89. in a single word, what was the result of the Avery, McCarty, and Macleod experiment involving the mice?
  90. What was the point of the Hershey and Chase experiment?
    Something along the lines of
  91. What is the name of the genetic material that is “cut out” of the pre-mRNA strand to yield mRNA?
  92. What are the 3 stop codons?
    uag uga uaa
  93. What type of mutation has no effect on the amino acid produced by a codonbecause of redundancy of the genetic code
    silent mutation
  94. What specific region of the promoter is necessary for the RNA polymerase to recognize and crucial in the formation of the initiation complex in transcription?