Mitosis Notes improved for honors

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Transcript Mitosis Notes improved for honors

Biology
Mitosis notes
Unicellular organisms - asexual
reproduction
Multicellular organisms- growth
& repair.
Figure 10–4 The Cell Cycle
Section 10-2
G1 phase
M phase
S phase
G2 phase
Cell Cycle
• Interphase - the longest part of the
cell cycle: growth, metabolism &
preparation for division occurs.
• Mitosis- the division of the nucleus.
• Cytokinesis - the division of the
cytoplasm.
Interphase
(In-between)
• Part of the cell cycle, not a
part of Mitosis.
• Longest part of the cell cycle
• Growth, metabolism, &
preparation for division occurs.
• Chromosomes are replicated.
The Steps of Mitosis
• PMAT
• Mitosis is the division
of the nucleus
producing two cells
with the same number
of chromosomes.
Prophase
(Preparing)
• Longest phase of mitosis
• Nuclear envelope &
nucleous disappears.
• Chromosomes become
visible.
• Centrioles (animal cell)
form and move to
opposite poles of cell
• Spindle fibers form from
centrioles, cross cell and
attach to the
chromosomes.
Metaphase
(middle)
Chromosomes
line up in the
middle of the
cell.
Spindles are
attached to
them.
Anaphase
(Apart)
• Spindle fibers
begin to shorten.
• This pulls
chromosomes
apart.
• Chromosome
halves are now
referred to as
chromatids.
Telophase
(Two cells)
• Chromatids reach
poles.
• Chromosomes
become chromatin.
• Spindle fibers break
down.
• Nucleolus and
nuclear envelope
appear.
Cytokinesis
(happens after telophase)
• Division of cytoplasm
• In animal cells: cell
membrane continues to
pinch in until two cells are
formed
• In plant cells: cell plate
forms in center of cell and
eventually splits cells
• At the end of cell division,
two new “daughter” cells
are produced.