bio 121 test 3

  1. Mitotic (M) phase of the cell cycle alternates with the much longer ________
  2. M phase includes
    mitosis and cytokinesis
  3. interphase accounts for ___% of the cell cycle
  4. during interphase, the cell grows by:
    producing ________ and cytoplasmic organelles
    copies its ________
    and prepares for ________ ________
    proteins/chromosomes/cell division
  5. G1 phase of interphase
    • "first gap"
    • centered on growth
  6. S phase of interphase
    • "synthesis"
    • when the chromosomes are copied
  7. G2 phase of interphase
    • "second gap"
    • where the cell completes preparations for cell division
  8. M phase of interphase
    cell divides
  9. mitosis is broken down into 5 subphases:
    • 1. prophase
    • 2. prometaphase
    • 3. metaphase
    • 4. anaphase
    • 5. telophase
  10. by late interphase, the chromosomes have been duplicated but are ________ packed. the centrosomes have been duplicated and begin to organize microtubules into an ________ ("star")

    loosely, aster
  11. -chromosomes are tightly coiled with sister chromatids joined together
    -nucleoli disappear
    -mitotic spindle begins to form and appears to push the centrosomes away from each other toward opposite ends of the cell
  12. -nuclear envelope fragments and microtubules from the spindle interact with the chromosomes
    -microtubules from one pole attach to one of two ________, special regions of the centromere, while microtubules from the other pole attach to the other ________
  13. the spindle fibers push the sister chromatids until they are all arranged at the ________ ________, an imaginary plane equidistant between the poles, defining metaphase
    metaphase plate
  14. -centromeres divide, separating sister chromatids
    -each is now pulled toward the pole to which it is attached by spindle fibers
    -by the end, the two poles have equivalent collections of chromosomes
  15. -cell continues to elongate as free spindle fibers from each centrosome push off each other
    -two nuclei begin to form, surrounded by the fragments of the parent's nuclear envelope
    -chromatin becomes less tightly coiled
    -cytokinesis begins
  16. cytokinesis
    division of the cytoplasm
  17. in animals, first sign of cytokinesis (cleavage) is the appearance of a cleavage ________ in the cell surface near the old metaphase plate
  18. -on the cytoplasmic side of the cleavage furrow, a contractile ring of actin microfilaments and the motor protein myosin form
    -________ of the ring pinches the cell in two
  19. cytokinesis in plants, which have cell walls, involves a completely different mechanism.
    -during telophase, vesicles from the Golgi coalesce at the metaphase plate, forming a ________ ________
    cell plate
  20. mitosis in eukaryotes may have evolved from binary fission in bacteria
    >prokaryotes reproduce by ________ ________, not mitosis
    binary fission
  21. in binary fission, chromosome replication begins at one point in the circular chromosome, the ________ of ________ ________
    -these copied regions begin to move to opposite ends of the cell
    origin of replication site
  22. cell division involved inward growth of the ________ ________, dividing the parent cell into two daughter cells, each with a complete genome
    plasma membrane
  23. generation-to-generation sequence of stages in the reproductive history of an organism
    -starts at conception of an organism until it produces its own offspring
    life cycle
  24. in humans, each somatic cell (all cells other than sperm or ovum) has ________ chromosomes
  25. a ________ display of the 46 chromosomes shows 23 pairs of chromosomes, each pair with the same length, centromere position, and staining pattern
  26. these ________ chromosome pairs carry genes that control the same inherited characters
  27. an exception to the rule of homologous chromosomes is found in the ________ chromosomes, the X and the Y
  28. homologous pair of X chromosomes (XX)
  29. have an X and a Y chromosome (XY)
  30. a cell with a single chromosome set is ________
    -for humans, the ________ number of chromosomes is 23 (n=23)
  31. gametes, which develop in the gonads, are/are not produced by mitosis
    are not > instead, gametes undergo the process of meiosis in which the chromosome number is halved
  32. all cells with two sets of chromosomes are ________ cells
    -for humans, the ________ number of chromosomes is 46 (2n=46)
  33. ________ restores the diploid condition by combining two haploid sets of chromosomes
    ________ and meiosis alternate in sexual life cycles
  34. after fusion of two gametes to form a zygote, the zygote undergoes ________ to produce haploid cells
    -these haploid cells undergo mitosis to develop into a haploid multicellular adult organism
  35. in ________ I, the chromosomes condense and homologous chromosomes pair up to form tetrads
  36. at ________ I, the tetrads are all arranged at the metaphase plate
  37. in ________ I, the homologous chromosomes separate and are pulled toward opposite poles
  38. in ________ I, movement of homologous chromosomes continues until there is a haploid set at each pole, each chromosome consists of linked sister chromatids
  39. pleiotropy
    influence of one gene over many characters
  40. epistasis
    direct influence of one gene on another
  41. polygenes
  42. polyploidy
    more than one set of chromosomes
  43. aneuploidy
    extra or missing chromosome, ex: down syndrome
  44. haploid sperm reaches and fuses with haploid ovum, resulting in
  45. asexual division
    does not involve having a partner
    increase #'s
    identical to parent cells
  46. sexual division
    results in increasing variability
  47. study of heredity and variation
  48. the transmission of traits from one generation to the next is ________
  49. offspring somewhat differ from parents/siblings because of _______
  50. when cells turn cancerous, alter cell regulation
  51. uncontrolled growth (of cells)
  52. mass of abnormal cells
  53. cancers occur in ________ ________ cells
    actively dividing
  54. if abnormal cells remain at originating site, lump is a ________ tumor
    -usually can be removed by surgery and do not cause serious problems
  55. cells leave origin to impair functions of one or more other organs
    malignant tumor
  56. cancer cells often lose attachment to nearby cells, are carried by blood and lymph system to other tissues, and start creating more tumors
  57. treatments for metastasizing cancers include:
    -target actively dividing cells
    • high energy radiation
    • chemotherapy with toxic drugs
  58. nuclear envelope fragments and microtubules from spindle interact with chromosomes
  59. centromeres divide, separating sister chromatids
  60. chromosomes line up
  61. cell continues to elongate as free spindle fibers from each centrosome pushing off each other
  62. divides the cytoplasm, typically follows mitosis
    -in animals, first sign of ________ is appearance of cleavage furrow
  63. prokaryotes reproduce by ________ ________, not mitosis
    binary fission
  64. "first gap"
    centered on growth
    G1 phase
  65. "synthesis"
    chromosomes copied
    S phase
  66. "second gap"
    cell completes preparation for cell division
    G2 phase
  67. cell divides
Card Set
bio 121 test 3
bio 121 test 3