Chapter 12 Packet

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Chapter 12 Packet
2011-01-04 22:20:22
Cell Cycle

AP Bio
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  1. What are the three key roles of cell division?
    • Reproduction
    • Growth and development
    • Tissue Removal
  2. What is meant by the cell cycle?
    life of a cell from the time its first formed from a dividing parent cell until its own division into two cells
  3. One of the three key roles:
    -- an amoeba, a single celled eukaryote divides into two cells; each new cell will be an individual organism
  4. a sand dollar embryo shortly after the fertilized egg divided, forming two cells
    growth and development
  5. the dividing bone marrow cells will give rise to new blood cells
    tissue renewal
  6. What is a genome?
    a cell's endowment of DNA; its genetic info
  7. Compare prokearyotic and eukaryotic genomes.
    • Prokaryotic:
    • --> one circular bacterial chromosome; single; no organelles; no nucleus
    • Eukaryotic:
    • --> # of DNA molecules; overall length- ENORMOUS; characteristic # in each cell nucleus
  8. How many chromosomes are in a human somatic cell?
    46 (2 sets of 23)
  9. What is a gamete?
    reproductive cell; unite during sexual reproduction (fertilization) to produce a diploid zygote; half as many chromosomes as somatic cells; one set of 23 chromosomes in humans
  10. Name two types of gametes.
    • sperm
    • eggs
  11. How many chromosomes in a human gamete?
    one set of 23
  12. Define chromatin.
    • a complex of DNA and associated protein molecules
    • - called this when a cell is not dividing
  13. How many DNA molecules are in each somatic cell?
  14. a cellular structure carrying genetic material, found in the nucleus of eukaryotic cells. Each consists of a very long DNA molecule and associated proteins; a bacterial one usually consists of a single circular DNA molecule and associated proteins found in the nucleoid region, which is not membrane bound
  15. each duplicate chromosome has two asister ones that each contain an identical DNA molecule, initially attached all along their lengths by adhesive protein complexes called cohesins
  16. specialized region of the chromosome where two sister chromatids are most closely attached
  17. COMPLEX OF dna AND PROTEINS THAT MAKE UP A EUKARYOTIC CHROMOSOME. wHEn the cell is not dividing, it exists in its dispersed replicated chromosome form, as a mass of very long, thin fibers that are not visible with a light microscope
  18. What is mitosis? cytokinesis?
    • division of the nucleus
    • division of the cytoplasm
  19. What occurs in meiosis?
    How is the chromosome number of daughter cells different?
    • produce gametes; modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division, but only one round of DNA replication;
    • yields nonidentical daughter cells that have only one set of chromosomes thus half as many chromosomes as the parent cell
  20. By what process are the damaged cells in a wound replaced?
  21. By what process are eggs formed?
  22. By what process does a zygote develop into a multicellular organism?
  23. In which process are identical daughter cells produced?
  24. Which process reduces chromosome # of daughter cells?
  25. A cell grows/ first gap
  26. continues to grow as it copies its chromosomes- chromosomes duplicate (synthesis)
  27. completes preparation for cell division (second gap)
  28. divides= mitotis
  29. What are the components of the mitotic spindle?
    • centrosomes
    • spindle microtubules
    • asters
    • (microtubules/ proteins)
  30. What is another name for the centrosome?
    microtubule-organizing center
  31. What happens to the centrosome during interphase and prophase?
    • Interphase: centrosomes are duplicated, resulting in two, but they remain together until prophase
    • Prophase: centrosome begins to separate with microtubules forming between them
  32. a structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle
  33. What is the difference between kinetochore and nonkinetochore microtubules?
    • kinetochore: microtubules that attach to kinetochores at the centromere of sister chromatids
    • non: do not attach to kinetochores and continue elongating and overlapping
  34. At wich end do kinetochore microtubules shorten during anaphase?
    the kinetochore ends; metaphase plate end
  35. Describe cytokinesis in an animal cell.
    • a process called cleavage
    • forms a cleavage furrow
    • on cytoplasmic side of the furrow is a contractile ring of actin filaments associated with myosin molecules
    • actin microfilaments interact with the myosin molecules, causing the ring to contract
    • cleavage furrow deepens until the parent cell is pinched in two, producing two completely separated cells, each with its own nucleus and share of cytosol, organelles, etc.
  36. Describe cytokinesis in plant cells.
    • no cleavage furrow
    • during telophase, vesicles derived from Golgi move along microfilaments to center of cell, where they coalesce forming a cell plate. Cell wall materials carried in the vesicles collect in the cell plate as it grows
    • cell plate enlarges until it fuses with membrane
    • two daughter cells result,e ach with own plasma membrane
    • a new cell wall arising from the chontents of the cell plate has formed between the daughter cells
  37. a method of asexual reproduction by division in 1/2. in prokaryotes, it does not involve mitosis, but in single-celled eukaryotes that undergo it, mitosis is part of the process
    binary fission
  38. Difference between prokaryotic reproduction and eukaryotic.
    • Prokaryotic: binary fission; one chromosome; circular DNA molecule
    • Eukaryotic: mitosis: varies in amt. of chromosomes; double helix