[PPT]The Cell Cyclemrspbiology.wikispaces.com/file/view/The+Cell+Cycle... · Web viewThe Cell Cycle copyright cmassengale Five Phases of the Cell Cycle G 1 - primary growth phase

The Cell Cycle

The Cell Cycle

copyright cmassengale

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1

Five Phases of the Cell Cycle

G1 - primary growth phase

S synthesis; DNA replicated

G2 - secondary growth phase

collectively these 3 stages are called interphase

M - mitosis

C - cytokinesis


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2

Cell Cycle


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3

Interphase - G1 Stage

1st growth stage after cell division

Cells mature by making more cytoplasm & organelles

Cell carries on its normal metabolic activities


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4

Interphase S Stage

Synthesis stage

DNA is copied or replicated


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Two identical copies of DNA

Original DNA

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Interphase G2 Stage

2nd Growth Stage

Occurs after DNA has been copied

All cell structures needed for division are made (e.g. centrioles)

Both organelles & proteins are synthesized


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6

Whats Happening in Interphase?


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What the cell looks like

Animal Cell

Whats occurring

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Sketch the Cell Cycle


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Daughter Cells

DNA Copied

Cells Mature

Cells prepare for Division

Cell Divides into Identical cells

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Mitosis


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Mitosis

Division of the nucleus

Also called karyokinesis

Only occurs in eukaryotes

Has four stages

Doesnt occur in some cells such as brain cells


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Four Mitotic Stages

Prophase

Metaphase

Anaphase

Telophase


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11

Early Prophase

Chromatin in nucleus condenses to form visible chromosomes

Mitotic spindle forms from fibers in cytoskeleton or centrioles (animal)


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Chromosomes

Nucleolus

Cytoplasm

Nuclear Membrane

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Late Prophase

Nuclear membrane & nucleolus are broken down

Chromosomes continue condensing & are clearly visible

Spindle fibers called kinetochores attach to the centromere of each chromosome

Spindle finishes forming between the poles of the cell


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13

Late Prophase


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Nucleus & Nucleolus have disintegrated

Chromosomes

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Spindle Fiber attached to Chromosome


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Kinetochore Fiber

Chromosome

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Review of Prophase


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Whats happening

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Spindle Fibers

The mitotic spindle form from the microtubules in plants and centrioles in animal cells

Polar fibers extend from one pole of the cell to the opposite pole

Kinetochore fibers extend from the pole to the centromere of the chromosome to which they attach

Asters are short fibers radiating from centrioles


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17

Sketch The Spindle


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Metaphase

Chromosomes, attached to the kinetochore fibers, move to the center of the cell

Chromosomes are now lined up at the equator


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Pole of the Cell

Equator of Cell

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Metaphase


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Chromosomes lined at the Equator

Asters at the poles

Spindle Fibers

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Metaphase


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Aster

Chromosomes at Equator

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Review of Metaphase


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Whats occurring

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Anaphase

Occurs rapidly

Sister chromatids are pulled apart to opposite poles of the cell by kinetochore fibers


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Anaphase


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Sister Chromatids being separated

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Anaphase Review


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Whats occurring

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Telophase

Sister chromatids at opposite poles

Spindle disassembles

Nuclear envelope forms around each set of sister chromatids

Nucleolus reappears

CYTOKINESIS occurs

Chromosomes reappear as chromatin


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Comparison of Anaphase & Telophase


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Cytokinesis

Means division of the cytoplasm

Division of cell into two, identical halves called daughter cells

In plant cells, cell plate forms at the equator to divide cell

In animal cells, cleavage furrow forms to split cell


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Cytokinesis


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Cleavage furrow in animal cell

Cell plate in plant cell

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Mitotic Stages


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Daughter Cells of Mitosis

Have the same number of chromosomes as each other and as the parent cell from which they were formed

Identical to each other, but smaller than parent cell

Must grow in size to become mature cells (G1 of Interphase)


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Identical Daughter Cells


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Chromosome number the same, but cells smaller than parent cell

What is the 2n or diploid number?

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Review of Mitosis


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Draw & Learn these Stages


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Draw & Learn these Stages


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Name the Mitotic Stages:


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Interphase

Prophase

Metaphase

Anaphase

Telophase

Name this?

Name this?

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Eukaryotic Cell Division

Used for growth and repair

Produce two new cells identical to the original cell

Cells are diploid (2n)


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Chromosomes during Metaphase of mitosis

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis

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Mitosis Animation


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Name each stage as you see it occur?

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Mitosis in Onion Root Tips


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Do you see any stages of mitosis?

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Test Yourself over Mitosis


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Mitosis Quiz


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Mitosis Quiz


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Name the Stages of Mitosis:


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Interphase

Early prophase

Mid-Prophase

Late Prophase

Metaphase

Late Anaphase

Early Anaphase

Early Telophase,

Begin cytokinesis

Late telophase,

Advanced cytokinesis

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Identify the Stages


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Early, Middle, & Late Prophase

Late Prophase

Metaphase

Anaphase

Late Anaphase

Telophase

Telophase & Cytokinesis

?

?

?

?

?

?

?

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Locate the Four Mitotic Stages in Plants


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Metaphase

Prophase

Anaphase

Telophase

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Uncontrolled Mitosis

If mitosis is not controlled, unlimited cell division occurs causing cancerous tumors

Oncogenes are special proteins that increase the chance that a normal cell develops into a tumor cell


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Cancer cells

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[PPT]The Cell Cyclemrspbiology.wikispaces.com/file/view/The+Cell+Cycle... · Web viewThe Cell Cycle copyright cmassengale Five Phases of the Cell Cycle G 1 - primary growth phase

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