Download Mitosis Notes

Mitosis Notes
CELL DIVISION
• 1 cell ÷ into 2 identical daughter cells
(same genetic info)
• Eukaryotes (cells w/ nucleus) go through 2
stages of ÷
• Mitosis – ÷ of nucleus
– Cytokinesis – ÷ of cytoplasm
Cell cycle = Life span of the cell
 G1 phase – cell grows,
makes more organelles &
proteins
 S phase – chromosome
replication (S = synthesis
= “to make”)
 G2 phase – molecules &
organelles required for
cell ÷ produced
 M phase – mitosis &
cytokinesis
G1 phase
S phase
G2 phase
Cell cycle = Life span of the cell
cont…
• G1, S and G2 make up INTERPHASE.
Cell spends a majority of its life in this
phase.
• M phase is CELL ÷. Relatively small
portion of cell’s life.
MITOSIS
• 4 phases of nuclear division
Prophase
• Longest phase of mitosis
• Chromosomes become
visible
• Centriole pairs begin to
separate
• Spindle fiber forms (made
of microtubules)
• Nuclear envelope breaks
down
• Spindle begins to attach
to chromosomes at
centromere
Metaphase
• Chromosomes line up
across center of the
cell
• Centromere
connected to spindle
fibers
• Centriole pairs at
opposite ends of cell
Anaphase
• Sister chromatid split
apart
• Chromosomes get
pulled to opposite
poles by shrinking
spindle fibers
• Chromosomes form
“V” shape as they get
dragged through the
cytoplasm
Telophase
• Chromosomes
decondence
• Nuclear envelope
reforms around each
set of chromosomes
at opposite ends of
cell
• Spindle fiber breaks
apart
• 2 nuclei are formed
Cytokinesis
• ÷ of cytoplasm
• 2 new daughter cells
are formed w/ same
number of
chromosomes as
original cell.
Video of Mitosis
• Mitosis Movie
• http://www.cellsalive.com/mitosis.htm
• http://www.youtube.com/watch?v=CzPGhYiGyZ8
• http://www.youtube.com/watch?v=vFf2dWZZtVg
Homework
• Obj. 14.1 and 14.2
(Meiosis)
• Make a special table
where you write
similarities and
differences between
Meiosis and Mitosis or a
Venn Diagram
• Discuss and stamp
Wednesday
• Current Event due Friday
• Friday, last day to turn in
progress reports (signed)
Similarities
Differences