Post on 28-Dec-2015
Chapter 10: Cell Growth and Division
10-1 Cell Growth10-2 Cell Division10-3 Regulating the Cell Cycle
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Chromatin Chromosomes Gene
Sister ChromatidsCell Cycle
Interphase
Mitosis
Prophase
Metaphase
Anaphase
Telophase
Centromere
Centrioles
Spindle
Cell Plate
Cleavage FurrowCytokinesis
Cyclin
Chapter 10 Concept Map pg. 244-249
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Results of MitosisTissue
Organ
Organ SystemCancer
Tumor
Types of Skin Cancer
Squamous Cell Carcinoma
Melanomas
Basal Cell Carcinoma Malignant Melanoma
Chapter 10 Concept Map pg. 250-252
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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 can’t 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 DivisionMitosis: 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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ProphaseFirst and longest phase of mitosisChromosomes 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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ProphaseSpindle Fibers One Chromosome
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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MetaphaseOne 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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AnaphaseChromatids 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
InterphaseProphase
MetaphaseAnaphaseTelophase
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Control of the Cell CycleA series of enzymes (cyclins, etc.) monitor a cell’s 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
http://dermis.multimedica.de/doia/image.asp?zugr=d&lang=e&cd=67&nr=61&diagnr=173922
Basal Cell Carcinoma
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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
BenignMalignan
t
Symmetrical
Asymetrical
Borders are even
Borders are uneven
One shade
Two or more shades
Smaller than 1/4 inch
Larger than 1/4
http://www.skincancer.org/skin-cancer/melanoma/melanoma_2.html
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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
Cell Size Limitatio
ns
Surface area to volume
Volume increases faster than surface area: Cell doubles in sizeArea increases 4xVolume increase 8x
Large cells without enough DNA cannot produce proteins fast enough
Diffusion
DNA
Too slow to transport material in a large cell (BIG volume)
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Control of the Cell Cycle Circle Map
Control of the Cell
Cycle
Enzymes monitor the progress of a cell from
phase to phase.
Enzyme production directed by genes.
Too many or too few disrupt cell cycle
Disrupted cell cycle results in cancer.
Wrong enzyme
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Cell Cycle Tree MapCell Cycle
Interphase
Longest phase of the cell cycleGrowth phaseCarries out metabolismChromosomes duplicatedCell parts assembled for cell division
Mitosis
Prophase
1st phaseLongest of mitosisChromosomes visibleNucleus/Nucleolus dissolveCentrioles migrate to opposite ends of the cellSister chromatids
Metaphase
Chromatids line up at the equatorAttached to the centromere
Anaphase
Sister chromatids begin to separatePulled by spindle fibers
Telophase
Chromatids at opposite ends
Cleavage furrow
Cell plateTwo daughter
cells formedNucleus and
nuclear envelope reappear
Cytokinesis
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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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