Transcript Stages of Mitosis

Stages of Mitosis
Eukaryotic Cell Division
Cell Division Facts
• All living organisms start out from
a single cell
• The average Human has about
10 trillion cells!
Chromosomes
• During interpahse,
genetic material
exists as chromatin
(DNA coiled around
histones)
• To prevent from
getting tangled during
division DNA coils
further into
Chromosomes.
Chromosome = 2 Chromatids
• Sister chromatids are copies of the exact
same chromosome (same DNA sequence)
• chromatid =1/2 of a replicated
chromosome
• Held together by a centromere
Interphase: Between Divisions, Cell
is preparing to divide
• G1 phase = growth phase, cell gets bigger
• S phase = synthesis phase, DNA
replicates
• G2 phase = Organelles multiply
Mitosis
PROPHASE
•
•
•
•
Chromatin coils into
chromosomes
Nuclear envelope
breaks down
Spindle fibers and
centrioles from
Centrioles move to
opposite ends of cell
METAPHASE
• Chromosomes are
moved to the center
of the cell by the
spindle fibers
• Centrioles act as
anchors for the spinal
fibers
ANAPHASE
• Centromeres split
apart
• Sister chromatids
are pulled apart by
spinal fibers
• Each chromatid is
now a separate
chromosome
Telophase / Cytokinesis
• Cytoplasm is divided into
• Cytokinesis is the
2 daughter cells
division of the
• Each daughter cell has its
chromosomes and
own set of chromosomes
organelles between
• Nuclear envelope reforms
the 2 daughter cells
• In plants a cell plate forms
between 2 daughter cells
• Chromosomes uncoil into
chromatin
• Note daughter cells are smaller
than surrounding cells
Websites to visit with Mitosis
animations
• http://www.biology.arizona.edu/Cell_bio/tutorials/
cell_cycle/cells3.html
• http://www.cellsalive.com/mitosis.htm
• http://www.johnkyrk.com/mitosis.html
• http://www.csuchico.edu/~jbell/Biol207/animation
s/mitosis.html
• http://www.sci.sdsu.edu/multimedia/mitosis/
• http://www.lewport.wnyric.org/jwanamaker/anima
tions/mitosis.html