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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