bio exam 2 ch. 9

  1. 2 major stages of the cell cycle
    • interphase
    • mitotic stage
  2. order of the cell cycle
    • G1
    • S   {interphase
    • G2

    M {Mitotic
  3. interphase details
    • is most of the cell cycle
    • consists of the cell's normal functions
    • varies by cell type
  4. 3 parts of interphase
    • G1 phase: cell matures; recovery and growth
    • S phase: DNA replication
    • G2 phase: preparation for division
  5. 2 parts of Mitotic stage
    results of mitotic stage
    • mitosis:nuclear division
    • daughter chromosomes are distributed by the mitotic spindle to two daughter nuclei
    • no change in number of chromosomes
    • Cytokinesis: division of the cytoplasm
    • results: genetically identical daughter cells
  6. internal signals of cell cycle
    cyclin proteins: increase and decrease during cell cycle; control completion of cycle
  7. apoptosis
    • programmed cell death
    • the nucleus fragments
    • the plasma membrane blisters
    • the fragments are destroyed
    • it is the opposite of mitosis
  8. DNA is made of
  9. chromatin
    network of DNA strands associated proteins observed within a nucleus of a cell (ball of twine)
  10. centromere
    constriction where sister chromatids of a chromosome are held together
  11. chromatid
    following replication, a chromosomes consists of a pair of sister chromatids, held together at the centromere: each chromatid is comprised of a single DNA helix
  12. centrosome
    • microtubule organizing center in animal cells
    • organizes mitotic spindle
    • replicated in the S phase
    • need two before mitosis begins
  13. diploid (2N)
    total number of chromosomes; for humans is 46
  14. haploid (N)
    half number of chromosomes; for humans is 23
  15. zygote
    result of fertilization; it is always diploid chromosome (46 in humans)
  16. at the end of the S phase
    chromosomes are duplicated and attached by a centromere
  17. during mitosis
    • centromeres separate
    • sister chromatids separate- daughter chromosomes
    • sisters of each type are distributed to opposite daughter nuclei
  18. 5 Phases of Mitosis (nuclear division)
    • Prophase
    • Prometaphase
    • Metaphase
    • Anaphase
    • Telophase
  19. prophase
    • chromatin condensed: each chromosome with 2 sister chromatids attached centromere
    • Nucleolus disappears
    • Nuclear envelope disintegrates
    • spindle begins to assemble
    • two centrosomes move away from each other
  20. prometaphase
    • centromere develops two kinetochores
    • connect sister chromatids to opposite poles of mother cell with kinetochores
    • kinetochores-fish hooks
    • spindle fibers-fishing line
    • daughter chromosomes- fish
  21. metaphase
    chromosomes (2 sister chromatids each) alighted at metaphase plate
  22. anaphase
    • 1. centromeres dissolve, sister chromatids separate and become daughter chromosomes
    • 2. daughter chromosomes begin to move toward opposite poles by the spindle
    • A for anaphase, A for Away
    • 3. cell membrane begins to pinch in (cleavage furrow)
  23. telophase
    • spindle disappears
    • nuclear envelope forms around chromosomes
    • nucleoli appear
    • new daughter cells form by furrowing
  24. cytokinesis
    • division of the cell (NOT nuclear division/mitosis)
    • division of cytoplasm (cleavage furrow)
    • mother cell cytoplasm equally distributed
    • each daughter cell gets own plasma membrane
  25. the entire sequence of interphase and mitosis
    • Interphase
    • Prophase
    • Prometaphase
    • Metaphase
    • Anaphase
    • Telophase
  26. cytokinesis in PLANT cells
    • cell plate forms:
    • vesicles align and fuse (sent by Golgi body)
    • one thin vesicle extending across the mother cell
    • space between daughter cells become filled and secrete primary cell walls
  27. functions of mitosis in multi-cellular and single-celled eukaryotes
    • multi-cellular: growth and repair
    • single celled: reproduction
  28. stem cells
    • they retain their ability to divide
    • used in therapeutic cloning- produces tissues
    • used in reproductive cloning- produces a new individual
  29. cancer
    uncontrolled cell division
  30. tumor
    abnormal growth of cells
  31. benign
    not cancerous
  32. malignant
  33. cause of cancer
    cancer develops when the delicate balance between promotion and inhibition of cell division is tilted toward uncontrollable cell division
  34. development of cancer
    • gradual development
    • metastasize- when  cancer moves from one part to another
  35. characteristics of cancer cells
    • no differentiation
    • have abnormal nuclei
    • do not undergo apoptosis
    • (immortal, abnormal, non-specialized)
  36. angiogenesis
    the growth of new blood vessels in and around tumors
  37. 2 types of genes affected by cancer
    • proto-oncogenes: code for proteins that speed up cell cycle and prevent apoptosis
    • tumor suppressor genes: code for proteins that slow down the cell cycle and promote apoptosis
  38. oncogenes
    cancer-causing genes that keep promoting cell cycle regardless of circumstances
  39. telomeres
    mutations in telomeres
    • the ends of the  chromosome
    • mutation causes telomeres to continue to lengthen and allows cancer cells to continually divide
  40. Asexual reproduction
    • occurs in prokaryotic cells by binary fission
    • only needs 1 parent
    • offspring are genetically identical to parent
  41. binary fission
    process by which prokaryotes reproduce asexually. the division (fission) produces 2 (binary) daughter cells that identical to the parent
  42. 5 steps of binary fission
    • attach: chromosome to special plasma membrane
    • grow: cell prepares by enlarging overall volume
    • replicate: DNA rep produces 2 identical chromosomes
    • elongate: as cell elongates, chromosomes pulled apart and cytoplasm distributed
    • equally
    • divide: new cell wall and plasma membrane has divided the daughter cells
  43. types of cell division for prokaryotes
    function of cell division for prokaryotes
    • bacteria and archaea: binary fission
    • function: asexual reproduction
  44. types of cell division for eukaryotes
    function of cell division for eukaryotes
    • Protists & some fungi: mitosis and cytokinesis
    • function: asexual reproduction
    • Other fungi, plants and animals: mitosis and cytokinesis
    • function: development, growth, and repair
Card Set
bio exam 2 ch. 9
biology, the cell cycle, chapter 9, midlands tech