Cellular Division in Eukaryotic CellsMitosis

Catherine AulicinoIntroduction

Interphase

Prophase

Prometaphase

Metaphase

Anaphase

Telophase

Cytokinesis NEXT

Introduction• Use this WebQuest to learn about each stage of mitosis and

answer the questions.

• Nuclear Division in Eukaryotes– Mitosis is the process of nuclear division of

eukaryotic cells that produce daughter nuclei that are genetically identical to the parent nucleus.

– What are the main functions of mitosis?http://plaza.ufl.edu/alallen/pgl/modules/rio/stingarees/module/what.html

– Describe the structure and function of the basic cell parts involved in Mitosis. http://plaza.ufl.edu/alallen/pgl/modules/rio/stingarees/module/index.html

Introduction Interphase Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis

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Interphase• Interphase prepares the cell to

undergo cell division. • The G1, S, and G2 phase take place

during interphase. What are these terms short for?

- http://www.phschool.com/science/biology_place/biocoach/mitosisisg/cellcyc.html

1. G1 Phase: Cellular content, excluding the chromosomes, are duplicated.

2. S Phase: DNA replication and chromatid duplication.

3. G2 Phase: The cell “double checks” the duplicated chromosomes for error, and makes repairs before entering mitosis.

Introduction Interphase Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis

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Prophase• Coil to shape

– The nucleolus fades and the chromatin (replicated DNA and proteins) condense into coiled chromosomes and are held together at the centromere. • Identical chromosomes appear as the letter “X”

– Nuclear envelope begins to break down.– The mitotic spindle, consisting of

microtubules, begins to form and migrate toward the ends of the cell.

– What happens during prophase to signal the beginning of prometaphase? http://www.phschool.com/science/biology_place/biocoach/mitosisisg/prophase.html

Introduction Interphase Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis

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Prometaphsae• The nuclear evelope

breaks down so there is no longer a recognizable nucleus.

• The mitotic spindle microtubules elongate from the centrosomes and move toward the the kinetochores.– What are kinetochores?

Where are they located? http://www.cellsalive.com/mitosis.htm

Introduction Interphase Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis

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Metaphase• Align & Attach– Identical chromosomes are

prepared for equal distribution between the two daughter cells. • The chromosomes become fully

attached to the mitotic spindle.• The chromosomes line-up at the

center of the cell, otherwise known as the metaphase plate.

Introduction Interphase Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis

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Anaphase• Divide and Drag

– Identical chromosomes are pulled apart so the cell can split in half• Centromeres divide, one for each

duplicated chromosome• Identical chromosomes separate

and are dragged by microtubules to opposite poles of the cell

• The cell becomes stretched and elongated

• What characteristic shapes appear during chromosome movement? http://www.phschool.com/science/biology_place/biocoach/mitosisisg/anaphase.html

Introduction Interphase Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis

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Telophase• Contract and Expand– The cell begins to restructure in preparation for

independence• Chromosomes arrive to the poles and uncoil• Mictrotubules break down• Nuclear envelopes form around chromosomes

Introduction Interphase Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis

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Cytokinesis

• Separate and Go Your Own Way– The cell finally splits into two

independent daughter cells.– In animal cells, cytokinesis

involves the formation of a __________ resulting in the pinching of the cell into two.

http

://www.phschool.com/science/biology_place/biocoach/mitosisisg/telo.html

Introduction Interphase Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis

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Rubic

• Each question is worth 5 points.• There are 7 questions.• Answers should be taken directly from the

websites provided in the webquest.