1. Chapter 10 Section 1 Cell Growth Pages 241-243
Explain the problems that growth causes for cells.
Describe how cell division solves the problems of cell growth.
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March 2005 1

2. Limits to Cell Growth larger cells have greater needs
DNA overload – information stored in DNA can no longer meet large cell’s needs
Material Exchange – cell has trouble moving enough food, oxygen, and water in and waste out through cell membrane.
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3. Ratio of Surface Area to Volume
As cells grow larger the surface area (cell membrane) does not grow as quickly as the volume (cell contents)
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4. Chapter 10 Section 2 Cell Division Pages 244-249
Name the main events of the cell cycle.
Describe what happens during the four phases of mitosis.
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5. The Cell Cycle Consists of FOUR (4) basic stages.
G1 Stage - cell grows, forms organelles, carries out its function.
S Stage - cell prepares for division by synthesis of DNA needed for new cells.
G2 Stage - cell grows producing proteins needed for cell division.
M Stage - cell divides to form 2 identical daughter cells.
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6. Cell Cycle
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7. Mitosis Consists of FOUR (4) basic stages.
Prophase - prepares nucleus and genetic material for division.
Metaphase - separates sister chromatids of chromosomes
Anaphase - movement of sister chromatids to opposite sides of cell.
Telophase - separates “old” cell into two smaller cells.
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8. Cytokinesis
This is the process by which the cytoplasm divides to form two daughter cells
Plants – a cell plate separates the new cells
Animals – the cell membrane pinches in to form a cleavage furrow
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9. Early Prophase nuclear envelope and nucleoli begin to disappear
chromatin condenses to form “doubled” chromosomes
centrioles migrate to opposite poles
spindle fibers form between the centrioles
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10. Late Prophase nuclear membrane and nucleolus are gone
centrioles have formed asters at the poles
spindle from each pole attaches to centromere of each chromosome
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11. Metaphase chromosomes line up at the equator of the cell
centromeres break separating each chromosome into “sister” or “daughter” chromatids
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12. Anaphase spindle guides chromatids to the poles
cell membrane begins to pinch in to begin to form cleavage furrow
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13. Telophase
cleavage furrow separates cytoplasm into 2 cells (cytokinesis)
nuclear membrane and nucleoli reappear
chromatids unwind to reform chromatin
spindle fibers disappear
centrioles reform centrosome
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14. No Centrioles, No Asters, and Cell Plate
Plant Mitosis
No Centrioles, No Asters, and Cell Plate
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15. Prophase nuclear envelope and nucleoli begin to disappear
chromatin condenses to form “doubled” chromosomes
spindle fibers appear in the cytoplasm
spindle attaches to centromeres of chromosomes
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March 2005 15

16. Metaphase chromosomes line up at the equator of the cell
centromeres break separating each chromosome into “sister” or “daughter” chromatids
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17. Anaphase spindle contracts to guide chromatids to the poles
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18. Telophase
cell plate forms at equator to separate cytoplasm into 2 cells
nuclear membrane and nucleoli reappear
spindle fibers disappear
chromatids unwind to reform chromatin
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19. Chapter 10 Section 3 Regulating the Cell Cycle Pages 250-252
Identify a factor that can stop cells from growing.
Describe how the cell cycle is regulated.
Explain how cancer cells are different from other cells.
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20. Controls on Cell Division
In culture dishes cells grow until they form a single layer
Growth stops when cell fill the dish
When cells are removed they will grow until they touch again
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21. Cell Cycle Regulators Cyclins regulate the timing of the cell cycle
Internal Regulators – respond to stimuli inside the cell
Example – cell can’t divide until DNA replicates
External Regulators - respond to stimuli outside the cell
Example – cells in embryos have markers on their surfaces that regulate their neighboring cell’s growth as they form tissues
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22. Uncontrolled Cell Growth
Cancer cells
Do not respond to growth signals
Form cell masses called tumors
Growth damages surrounding tissues
Cancer
disease caused by the uncontrolled cell division of abnormal cells
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23. Chapter 11 Section 4 Meiosis
Contrast the chromosome number of body cells and gametes.
Summarize the events of meiosis.
Contrast meiosis and mitosis.
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24. Chromosome Number Homologous Pairs Diploid (2n) Haploid (n)
Body cells contain two sets of chromosomes
One set comes from the male parent
One set comes from the female parent
Diploid (2n)
Cells that contain both sets of chromosomes
Body cells
Haploid (n)
Cells that contain only one set of chromosomes
Gametes (sex cells)
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25. Figure 11-15 Meiosis Meiosis I Interphase I Section 11-4 Prophase I
Metaphase I
Anaphase I
Cells undergo a round of DNA replication, forming duplicate Chromosomes.
Each chromosome pairs with its corresponding homologous chromosome to form a tetrad.
Spindle fibers attach to the chromosomes.
The fibers pull the homologous chromosomes toward the opposite ends of the cell.
Go to Section:
Updated January 2006
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March 2005 25

26. Figure 11-15 Meiosis Meiosis I Interphase I Section 11-4 Prophase I
Metaphase I
Anaphase I
Cells undergo a round of DNA replication, forming duplicate Chromosomes.
Each chromosome pairs with its corresponding homologous chromosome to form a tetrad.
Spindle fibers attach to the chromosomes.
The fibers pull the homologous chromosomes toward the opposite ends of the cell.
Go to Section:
Updated January 2006
Created by C. Ippolito
March 2005 26

27. Figure 11-15 Meiosis Meiosis I Interphase I Section 11-4 Prophase I
Metaphase I
Anaphase I
Cells undergo a round of DNA replication, forming duplicate Chromosomes.
Each chromosome pairs with its corresponding homologous chromosome to form a tetrad.
Spindle fibers attach to the chromosomes.
The fibers pull the homologous chromosomes toward the opposite ends of the cell.
Go to Section:
Updated January 2006
Created by C. Ippolito
March 2005 27

28. Figure 11-15 Meiosis Meiosis I Interphase I Section 11-4 Prophase I
Metaphase I
Anaphase I
Cells undergo a round of DNA replication, forming duplicate Chromosomes.
Each chromosome pairs with its corresponding homologous chromosome to form a tetrad.
Spindle fibers attach to the chromosomes.
The fibers pull the homologous chromosomes toward the opposite ends of the cell.
Go to Section:
Updated January 2006
Created by C. Ippolito
March 2005 28

29. Figure 11-17 Meiosis II Meiosis II Section 11-4 Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original.
The chromosomes line up in a similar way to the metaphase stage of mitosis.
The sister chromatids separate and move toward opposite ends of the cell.
Meiosis II results in four haploid (N) daughter cells.
Go to Section:
Updated January 2006
Created by C. Ippolito
March 2005 29

30. Figure 11-17 Meiosis II Meiosis II Section 11-4 Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original.
The chromosomes line up in a similar way to the metaphase stage of mitosis.
The sister chromatids separate and move toward opposite ends of the cell.
Meiosis II results in four haploid (N) daughter cells.
Go to Section:
Updated January 2006
Created by C. Ippolito
March 2005 30

31. Figure 11-17 Meiosis II Meiosis II Section 11-4 Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original.
The chromosomes line up in a similar way to the metaphase stage of mitosis.
The sister chromatids separate and move toward opposite ends of the cell.
Meiosis II results in four haploid (N) daughter cells.
Go to Section:
Updated January 2006
Created by C. Ippolito
March 2005 31

32. Figure 11-17 Meiosis II Meiosis II Section 11-4 Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original.
The chromosomes line up in a similar way to the metaphase stage of mitosis.
The sister chromatids separate and move toward opposite ends of the cell.
Meiosis II results in four haploid (N) daughter cells.
Go to Section:
Updated January 2006
Created by C. Ippolito
March 2005 32

33. Figure 11-17 Meiosis II Meiosis II Section 11-4 Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original.
The chromosomes line up in a similar way to the metaphase stage of mitosis.
The sister chromatids separate and move toward opposite ends of the cell.
Meiosis II results in four haploid (N) daughter cells.
Go to Section:
Updated January 2006
Created by C. Ippolito
March 2005 33

34. Gamete Formation Males Females Meiosis of diploid cell
Forms 4 haploid sperm cells
Females
Forms 1 haploid egg cell and 3 polar bodies that disintegrate
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March 2005 34

35. Comparison of Mitosis and Meiosis
Begins with diploid (2n) cell
One cell division
Forms two new cells
New cells genetically identical
Maintains chromosome number as diploid (2n)
Meiosis
Begins with diploid (2n) cell
Two cell divisions
Forms four new cells
New cells genetically different
Reduces chromosome number to haploid (n)
Updated January 2006
Created by C. Ippolito
March 2005 35