Mitosis

Interphase• Not technically part of

mitosis• Cell spends 99% time

in this phase• DNA exists in

___________ form• Cell performs…..?

* Most important Fact …

Prophase

Events of Prophase

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Prophase

• Is the cell to the left a human cell?

• How many chromosomes are pictured?

• Are the chromosomes normal size or duplicated?

• Which pieces of DNA are identical to each other?

Metaphase

• The duplicated chromosomes line up along the “equator” of the cell.

• What causes them to move?

Metaphase

• How many chromosomes are pictured?

• Are the two red “X”s identical to each other?

Anaphase

• Spindle fibers split the duplicated chromosomes in half.

• The identical chromatids are separated from each other…. But now they are normal sized chromosomes!

• Will the two daughter cells be genetically identical?

Telophase

• Telophase is called “reverse prophase” because…..

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Telophase

In telophase, cytokinesis occurs.

Cytokinesis -

Telophase

Q: Are the two daughter cells genetically identical to each other????

Clones -

MITOSIS – BIG IDEAS

• Occurs in all eukaryotic organisms

• Each chromosome is copied. (how?)One copy of each chromosome is distributed to both daughter cells.

• Thus All body cells contain full set of chromosomes (therefore full set of genes)

Questions

When do cells mitose?

What determines when cells start and stop mitosing?

Can you think of a medical condition in which you would like human cells to mitosis, (but they normally don’t)?