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Cell Division
Chromosomes
 Are
made of DNA
 Each chromosome consists of sister
chromatids attached at a centromere
Cell Cycle
 During
the cell cycle, a cell grows,
prepares for division, and divides to
form 2 daughter cells, each with
each of which then begins the cycle
again.
 Interphase – time for growth and
regular cell activity.
 Most of a cells life is spent in
Interphase.
Cell Cycle
Interphase
Introduction to Cell Division
Mitosis
 The
division of somatic or regular
cells.
 Its divided into 4 phases.
 Remember Interphase is NOT part of
Mitosis.
http://www.dnatube.com/video/45/Development-of-egg-cells
Introduction to Mitosis
Prophase
 First
stage of Mitosis
 Chromatin condenses into
chromosomes
 Centrioles separate and a spindle
fiber begins to form.
 Nuclear membrane breaks down
Prophase
Metaphase
 Second
Phase of Mitosis
 Chromosomes line up in the middle
of the cell.
 Each chromosome is connected to a
spindle fiber.
Metaphase
Anaphase
 Third
Phase of Mitosis
 The sister chromatids separate into
individual chromosomes and move
apart to opposite ends of the cell.
Anaphase
Telophase
 Fourth
and Final Stage of Mitosis
 Chromosomes gather at opposite
ends of the cell and lose their distinct
shapes
 Two new nuclear membranes have
formed.
Telophase
Cytokinesis
 The
cytoplasm pinches in half.
 Each daughter cell has an identical
set of duplicate chromosomes
When Things Go Wrong
 Cancer
cells do not respond to the
signals that regulate the growth of
most cells.
 As a result, they form masses of cells
called tumors that can damage
surrounding tissues.
Cancer