Chapter 10: Cell Growth and Division

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Chapter 10 Cell Growth and Division

• 10-1 Cell Growth
• 10-2 Cell Division
• 10-3 Regulating the Cell Cycle

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Chapter 10 Concept Map pg. 244-249
Gene
Chromatin
Chromosomes
Interphase
Sister Chromatids
Cell Cycle
Mitosis
Centromere
Cyclin
Prophase
Centrioles
Metaphase
Spindle
Anaphase
Cell Plate
Cytokinesis
Telophase
Cleavage Furrow
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Chapter 10 Concept Map pg. 250-252
Results of Mitosis
Tissue
Organ
Organ System
Cancer
Tumor
Types of Skin Cancer
Melanomas
Squamous Cell Carcinoma
Basal Cell Carcinoma
Malignant Melanoma
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Cell Growth

• Cell size limitations
• Surface area to volume ratio The volume of a
  cell increases faster than its surface area.
• Diffusion becomes inefficient at moving
  necessary materials in and out of cell when
  volume is too big
• DNA makes certain proteins necessary to all
  organelles. In a large cell without enough DNA,
  these proteins are not produced quickly enough.
• Information crisis cell cant meet all of its
  needs

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Cell Division

• Chromosomes Condensed clumps of DNA that are
  visible right before cell division, they unwind
  soon after.
• Tightly packed

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Chromosome Structure(like a ball of yarn)
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Cell Division

• The Cell Cycle The cycle of growth and division
  of a cell (interphase and mitosis).
• See Figure 10-4, pg. 245.

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Cell Division

• Interphase The growth period of a cell.
• 3 Parts
• G1 The cell grows in size and carries on
  metabolism (excretion, energy production, making
  proteins).
• S DNA replicated in preparation for cell
  division.
• G2 Cell parts needed for cell division are
  assembled.

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Cell Division

• Mitosis The phase of the cell cycle when the
  cell begins division NO VARIATION
• Occurs when cell size is at a maximum.
• Occurs in every cell of your body.
• Four distinct phases, or stages.
• Prophase
• Metaphase
• Anaphase
• Telophase

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Prophase

• First and longest phase of mitosis
• Chromosomes are visible (DNA condenses)
• Each half of a replicated chromosome is called a
  sister chromatid.
• They are exact copies of each other
• They are connected by a centromere.
• Scientists are often able to identify chromosomes
  by the location of the centromere.

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Prophase

• Nucleus and nucleolus dissolve
• They become no longer visible within the cell
• By late prophase, centrioles migrate toward
  opposite ends of the cell.
• Centrioles Structures made up of microtubules
  that aid in separation of sister chromatids.
• Spindle fibers many microtubules branching out
  from the centrioles. Created to pull apart
  sister chromatids.
• Plants just have spindle form without the help of
  centrioles.

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Prophase
One Chromosome
Spindle Fibers
Chromatid
Centrioles
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Metaphase middle

• Metaphase The centromeres on the sister
  chromatids become attached to the spindle fibers.
  The chromatids are then lined up in the middle
  of the cell.
• Each centromere has one spindle fiber on either
  side (one for each chromatid).
• These fibers come from the centrioles.

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Metaphase
One spindle fiber for each chromatid that makes
up the chromosome
Metaphase in an Onion
All chromosome line up in the middle
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Anaphase away, apart

• Anaphase the sister chromatids are separated
• The centromeres split and the sister chromatids
  are pulled apart.
• The chromatids are pulled by the spindle fibers
  toward the centrioles at the poles of the cell.

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Anaphase
Chromatids are pulled by spindles, and separate
Anaphase in an Onion
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Telophase

• Telophase Phase is characterized by cleavage
  furrow, or cell beginning to split its cytoplasm
  into two distinct daughter cells. Chromatids are
  now far away from each other.
• Chromosomes begin to unwind
• Spindle breaks down
• Nucleolus reappears
• Nuclear envelope forms again around chromosomes

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Cytokinesis

• Cytokinesis Cytoplasm of cell divides. Occurs
  after telophase.
• In a plant cell, a cell plate is laid down to
  separate the contents of the two cells. Plasma
  membranes form inside these new cell walls that
  have been created.

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Telophase leading into cytokinesis
Cell wall formation
Telophase into cytokinesis in an Onion
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I-P-M-A-T

• Interphase
• Prophase
• Metaphase
• Anaphase
• Telophase

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Control of the Cell Cycle

• A series of enzymes (cyclins, etc.) monitor a
  cells progress from phase to phase.
• Enzyme production is directed by genes
• Too many or too few of these enzymes can disrupt
  a normal cell cycle
• Also, the wrong enzyme production can disrupt the
  cell cycle
• Cancer a disrupted cell cycle can result in
  excessive cell division

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Control of the Cell Cycle

• Causes of Cancer
• Environmental factors
• Smoking
• Breast, mouth, lung, pancreatic, liver, etc.
• Exposure to sunlight (UV Radiation)
• Basal Cell, Malignant melanoma
• Diet
• Genetic Factors
• Faulty genes
• Viral infections

Basal Cell Carcinoma
http//dermis.multimedica.de/doia/image.asp?zugrd
langecd67nr61diagnr173922
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Types of Skin Cancers

• Basal Cell Carcinoma
• Most common type of skin cancer affecting the
  deepest layer of cells of the epidermis.
• Squamous Cell Carcinoma
• Second most common type of skin cancer.
• Malignant Melanoma
• Most dangerous type of skin cancer arising from
  pigmented areas of the skin.
• Incidents of this cancer have increased among
  young people due to increased sun exposure.

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ABCDE of Melanoma asymmetry, border, color,
diameter, evolving
http//www.skincancer.org/skin-cancer/melanoma/mel
anoma_2.html
Benign Malignant  
Symmetrical                           Asymetrical
Borders are even                           Borders are uneven
One shade                           Two or more shades
Smaller than 1/4 inch                           Larger than 1/4
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Control of the Cell Cycle

• An interesting fact Where you live is also an
  important factor in cancer rates
• When you move to a different country, your
  chances of getting different kinds of cancer
  change to those in your new country.
• The possibility of your getting certain cancers
  is no longer the same as it was in your original
  country
• Cancer Growth Website

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Cell Size Limitations Circle Map
Volume increases faster than surface area Cell
doubles in sizeArea increases 4xVolume increase
8x
Large cells without enough DNA cannot produce
proteins fast enough
Surface area to volume
Cell Size Limitations
DNA
Diffusion
Too slow to transport material in a large cell
(BIG volume)
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Control of the Cell Cycle Circle Map
Disrupted cell cycle results in cancer.
Enzyme production directed by genes.
Enzymes monitor the progress of a cell from phase
to phase.
Control of the Cell Cycle
Too many or too few disrupt cell cycle
Wrong enzyme
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Cell Cycle Tree Map
Cell Cycle
Mitosis
Interphase Longest phase of the cell cycleGrowth
phaseCarries out metabolismChromosomes
duplicatedCell parts assembled for cell division
Anaphase Sister chromatids begin to
separatePulled by spindle fibers
Metaphase Chromatids line up at the
equatorAttached to the centromere
Prophase 1st phaseLongest of mitosisChromosomes
visibleNucleus/Nucleolus dissolveCentrioles
migrate to opposite ends of the cellSister
chromatids
Telophase Chromatids at opposite endsCleavage
furrowCell plateTwo daughter cells
formedNucleus and nuclear envelope
reappearCytokinesis
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Causes of Cancer Tree Map
Causes of Cancer
Environmental SmokingSunlightDiet
Genetic Faulty genesViral infections
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Cell Cycle Flow Chart
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