Intro & How do Chromosomes behave

  1. The 5' end of DNA consists of:
    A free phosphate or hydroxyl on the no. 3 carbon of the sugar
  2. The 3' end of DNA consists of:
    A free hydroxyl group on the no. 3 carbon
  3. The sugar moiety in RNA is:
  4. DNA is replicated by __________ replication
  5. Elongation by DNA polymerase can only occur from ___' to ___'
    5' to 3'
  6. Messenger RNA represents the ______ of a segment of DNA
  7. There are ____ possible codons for ____ amino acids
    • 64
    • 20
  8. To synthesize a protein the mRNA must be _____
  9. transfer RNAs:
    Carry an amino acid
  10. Biological definiton of a gene:
    A trait or character which can be shown to have a simple pattern of inheritance
  11. Molecular definition of a gene:
    A specific sequence of DNA which codes for a particular protein, polypeptide or RNA sequence
  12. The typical sturcture of a gene consists of:
    a promoter, start codon, stop codon, regulators (enhancers), exons, and introns
  13. A diploid genmore consists of approximately _______base pairs
    6 billion
  14. Less than ___% of the genome encodes proteins or peptides
  15. The current consensus is that there are a total of ______-_____genes
    30,000-35,000 genes
  16. What is the rest of the genome?
    Approimately 90% consists of __________
    About 75% consists of ________
    The remainder once called _____
    About 10-15% consists of_____
    Unique or families of related sequences

    Single copy DNA-Pseudogenes

    Junk DNA

    Tandemly repeated sequences-Satellite DNA
  17. Each Chromosome is belived to consist of:
    A single double helix that forms a complex with nucleoproteins and represents packaging of genetic material, seen in non dividing cells as chromatin
  18. An average chromosome unwound is about ____ long
    2 meters
  19. Each chromosome is about ____ to ____ the length of its constituent DNA
    1/3,000th to 1/10,000
  20. When packaged DNA is coiled around a ____ to form a string of bead-like _____
    histone core

  21. Each nucleosome consists of
    an octamer of four differnt histones-2 copies of each
  22. The four types of nucleosomes:
    H2A, H2B, H3 and H4
  23. Approximatley ___bp of DNA are wrapped around each nucleosome seperated by a ___ bp spacer

  24. Solenoid
    a 30nm chromatin fiber resulting from secondary coiling of nucleosomes
  25. Solenoid fibers appear to be organized by attachment in the form of:
    loops to a non-histone protein scaffold
  26. Telomeres and gene-rich regions have a high ____content
  27. Centromeres and gene-poor regions tend to be ____ rich
  28. Constitutive heterochromatin
    Regions of the genomre that are genetically inert and remain condensed in interphase

    A permanent feature of the chromosome

    Reflected by a dif in staining of a particular chromosome region in both homologs
  29. Facultative heterochromatin
    Regions of the genome that are genetically inert due to dosage compensation

    herterochromatin associated with inactive X

    Not a permanent feature of the chromosome

    Does not effect banding pattern
  30. Single copy sequences make up ______ of the genome
    and ____ are translated into peptides or proteins
    • make up more than half of the genome
    • only 3%
  31. Dispersed repeated sequences make up approximately ___% of the genome and consits mainly of

    Alu (SINES, 300bp in length) and L1 or Kpn (LINES, 7-8 bp in lenght)
  32. LINES/L1 sequences correspond mainly to ______ or _____ and stain ____by these techniques
    G banding or Q banding and stain dark or moderately birght
  33. Short tandemly repeated sequences make up ~ ____ of the genome
    These include:
    • 10-15%
    • Satellite DNAs
    • microsatellite sequences
    • minisatellite sequences
    • telomeric sequences
  34. SINES/Alu sequences correspond mainly to _____ or____by ___and ___ banding
    Dark R bands or bands that stain pail by Q and G banding
  35. Transposable elements:
    When LINES and SINES generate copies of themselves and insert them elsewehere in the genome and alter gene expression to cause disease
  36. Satellite sequences are variably staining and are typically in the _____ regions of the chromosomes
  37. _________ are polymorphic markers that are heritable and used to map or ID genetic disorders by linkage, can identify genetic fingerprint
    Microsatellites and minisatellites
  38. Telomeric sequence
    Highty conserved and stablizes the ends of chromosome arms (prevent the gradual loss of DNA)
  39. Five phases of mitosis
    • Prophase
    • Prometaphase
    • Metaphase
    • Anaphase
    • Telophase
  40. Interphase
    • Stages G0-S
    • Majority of time in this phase
    • Chromosomes not individually visible
  41. G0
    Resting phase
  42. G1
    Protein synthesis; prep for S

  43. S
    • DNA synthesis
    • 6-8hours
  44. G2
    • Prophase
    • 2-4 hours
  45. M
    • Metaphase
    • 1-2 hours
  46. The lenght of the cell cycle is ___hours
  47. Metaphase is ____ long
    and is the period in which chromosomes are ______
    • Mose condensded and easily distinguishable under the microscope
    • Usually consist of 2 chromatids attached at the centromere
  48. The division of centromeres marks the begining of
  49. ________ can inhibit the division of centromeres by disrupting the formation of microtubules
  50. The DNA content in G1 is:
  51. The DNA content in S is
  52. The DNA content in G2
  53. The DNA content in M
  54. Daugter cells each have ____ of DNA
  55. Telophase
    Cell membrane begins to reform around each set of chromatids
  56. A birth the ova have already initiated ______ which remains in a suspended state of_____ until fertilization
    First meiotic cell division

  57. in males, first and second meiotic cell division resutlting in the formation of sperm occur at ______ and spermatogenesis is:

    ongoing througout reproductive life
  58. Leptotene
    • The initial pairing of paternal and maternal chromosomes
    • very percise
  59. The end of the pairing of maternal and paternal chromosomes is called
  60. Synaptonemal complex
    the structure holding the chromosomes together during pairing
  61. Pachytene
    the stage at which the chromosomes start to seperate in meiosis
Card Set
Intro & How do Chromosomes behave
Midterm review