Содержание
- 2. Overview: The Key Roles of Cell Division The ability of organisms to reproduce best distinguishes living
- 3. Fig. 12-1
- 4. In unicellular organisms, division of one cell reproduces the entire organism Multicellular organisms depend on cell
- 5. Fig. 12-2 100 µm 200 µm 20 µm (a) Reproduction (b) Growth and development (c) Tissue
- 6. Fig. 12-2a 100 µm (a) Reproduction
- 7. Fig. 12-2b 200 µm (b) Growth and development
- 8. Fig. 12-2c 20 µm (c) Tissue renewal
- 9. Concept 12.1: Cell division results in genetically identical daughter cells Most cell division results in daughter
- 10. Cellular Organization of the Genetic Material All the DNA in a cell constitutes the cell’s genome
- 11. Fig. 12-3 20 µm
- 12. Every eukaryotic species has a characteristic number of chromosomes in each cell nucleus Somatic cells (nonreproductive
- 13. Distribution of Chromosomes During Eukaryotic Cell Division In preparation for cell division, DNA is replicated and
- 14. Fig. 12-4 0.5 µm Chromosomes Chromosome duplication (including DNA synthesis) Chromo- some arm Centromere Sister chromatids
- 15. Eukaryotic cell division consists of: Mitosis, the division of the nucleus Cytokinesis, the division of the
- 16. Concept 12.2: The mitotic phase alternates with interphase in the cell cycle In 1882, the German
- 17. Phases of the Cell Cycle The cell cycle consists of Mitotic (M) phase (mitosis and cytokinesis)
- 18. Interphase (about 90% of the cell cycle) can be divided into subphases: G1 phase (“first gap”)
- 19. Fig. 12-5 S (DNA synthesis) MITOTIC (M) PHASE Mitosis Cytokinesis G1 G2 INTERPHASE
- 20. Mitosis is conventionally divided into five phases: Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis is well underway
- 21. Fig. 12-6 G2 of Interphase Centrosomes (with centriole pairs) Chromatin (duplicated) Nucleolus Nuclear envelope Plasma membrane
- 22. Prophase Fig. 12-6a Prometaphase G2 of Interphase
- 23. Fig. 12-6b Prometaphase Prophase G2 of Interphase Nonkinetochore microtubules Fragments of nuclear envelope Aster Centromere Early
- 24. Fig. 12-6c Metaphase Anaphase Telophase and Cytokinesis
- 25. Fig. 12-6d Metaphase Anaphase Telophase and Cytokinesis Cleavage furrow Nucleolus forming Metaphase plate Centrosome at one
- 26. The Mitotic Spindle: A Closer Look The mitotic spindle is an apparatus of microtubules that controls
- 27. An aster (a radial array of short microtubules) extends from each centrosome The spindle includes the
- 28. During prometaphase, some spindle microtubules attach to the kinetochores of chromosomes and begin to move the
- 29. Fig. 12-7 Microtubules Chromosomes Sister chromatids Aster Metaphase plate Centrosome Kineto- chores Kinetochore microtubules Overlapping nonkinetochore
- 30. In anaphase, sister chromatids separate and move along the kinetochore microtubules toward opposite ends of the
- 31. Fig. 12-8 EXPERIMENT Kinetochore RESULTS CONCLUSION Spindle pole Mark Chromosome movement Kinetochore Microtubule Motor protein Chromosome
- 32. Fig. 12-8a Kinetochore Spindle pole Mark EXPERIMENT RESULTS
- 33. Fig. 12-8b Kinetochore Microtubule Tubulin Subunits Chromosome Chromosome movement Motor protein CONCLUSION
- 34. Nonkinetochore microtubules from opposite poles overlap and push against each other, elongating the cell In telophase,
- 35. Cytokinesis: A Closer Look In animal cells, cytokinesis occurs by a process known as cleavage, forming
- 36. Video: Sea Urchin (Time Lapse) Video: Animal Mitosis Copyright © 2008 Pearson Education, Inc., publishing as
- 37. Fig. 12-9 Cleavage furrow 100 µm Contractile ring of microfilaments Daughter cells (a) Cleavage of an
- 38. Cleavage furrow Fig. 12-9a 100 µm Daughter cells (a) Cleavage of an animal cell (SEM) Contractile
- 39. Fig. 12-9b Daughter cells (b) Cell plate formation in a plant cell (TEM) Vesicles forming cell
- 40. Fig. 12-10 Chromatin condensing Metaphase Anaphase Telophase Prometaphase Nucleus Prophase 1 2 3 5 4 Nucleolus
- 41. Fig. 12-10a Nucleus Prophase 1 Nucleolus Chromatin condensing
- 42. Fig. 12-10b Prometaphase 2 Chromosomes
- 43. Fig. 12-10c Metaphase 3
- 44. Fig. 12-10d Anaphase 4
- 45. Fig. 12-10e Telophase 5 Cell plate 10 µm
- 46. Binary Fission Prokaryotes (bacteria and archaea) reproduce by a type of cell division called binary fission
- 47. Fig. 12-11-1 Origin of replication Two copies of origin E. coli cell Bacterial chromosome Plasma membrane
- 48. Fig. 12-11-2 Origin of replication Two copies of origin E. coli cell Bacterial chromosome Plasma membrane
- 49. Fig. 12-11-3 Origin of replication Two copies of origin E. coli cell Bacterial chromosome Plasma membrane
- 50. Fig. 12-11-4 Origin of replication Two copies of origin E. coli cell Bacterial chromosome Plasma membrane
- 51. The Evolution of Mitosis Since prokaryotes evolved before eukaryotes, mitosis probably evolved from binary fission Certain
- 52. Fig. 12-12 (a) Bacteria Bacterial chromosome Chromosomes Microtubules Intact nuclear envelope (b) Dinoflagellates Kinetochore microtubule Intact
- 53. Fig. 12-12ab Bacterial chromosome Chromosomes Microtubules (a) Bacteria (b) Dinoflagellates Intact nuclear envelope
- 54. Fig. 12-12cd Kinetochore microtubule (c) Diatoms and yeasts Kinetochore microtubule (d) Most eukaryotes Fragments of nuclear
- 55. Concept 12.3: The eukaryotic cell cycle is regulated by a molecular control system The frequency of
- 56. Evidence for Cytoplasmic Signals The cell cycle appears to be driven by specific chemical signals present
- 57. Fig. 12-13 Experiment 1 Experiment 2 EXPERIMENT RESULTS S G1 M G1 M M S S
- 58. The Cell Cycle Control System The sequential events of the cell cycle are directed by a
- 59. Fig. 12-14 S G1 M checkpoint G2 M Control system G1 checkpoint G2 checkpoint
- 60. For many cells, the G1 checkpoint seems to be the most important one If a cell
- 61. Fig. 12-15 G1 G0 G1 checkpoint Cell receives a go-ahead signal G1 (b) Cell does not
- 62. The Cell Cycle Clock: Cyclins and Cyclin-Dependent Kinases Two types of regulatory proteins are involved in
- 63. Fig. 12-16 Protein kinase activity (– ) % of dividing cells (– ) Time (min) 300
- 64. Fig. 12-17 M G1 S G2 M G1 S G2 M G1 MPF activity Cyclin concentration
- 65. Fig. 12-17a Time (a) Fluctuation of MPF activity and cyclin concentration during the cell cycle Cyclin
- 66. Fig. 12-17b Cyclin is degraded Cdk MPF Cdk M S G1 G2 checkpoint Degraded cyclin Cyclin
- 67. Stop and Go Signs: Internal and External Signals at the Checkpoints An example of an internal
- 68. Fig. 12-18 Petri plate Scalpels Cultured fibroblasts Without PDGF cells fail to divide With PDGF cells
- 69. Another example of external signals is density-dependent inhibition, in which crowded cells stop dividing Most animal
- 70. Fig. 12-19 Anchorage dependence Density-dependent inhibition Density-dependent inhibition (a) Normal mammalian cells (b) Cancer cells 25
- 71. Cancer cells exhibit neither density-dependent inhibition nor anchorage dependence Copyright © 2008 Pearson Education, Inc., publishing
- 72. Loss of Cell Cycle Controls in Cancer Cells Cancer cells do not respond normally to the
- 73. A normal cell is converted to a cancerous cell by a process called transformation Cancer cells
- 74. Fig. 12-20 Tumor A tumor grows from a single cancer cell. Glandular tissue Lymph vessel Blood
- 75. Fig. 12-UN1 Telophase and Cytokinesis Anaphase Metaphase Prometaphase Prophase MITOTIC (M) PHASE Cytokinesis Mitosis S G1
- 76. Fig. 12-UN2
- 77. Fig. 12-UN3
- 78. Fig. 12-UN4
- 79. Fig. 12-UN5
- 80. Fig. 12-UN6
- 81. You should now be able to: Describe the structural organization of the prokaryotic genome and the
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