Life of a Cell
The Cell Cycle and
Mitosis
Mitosis
(copy this information on the back of your Mitosis cut & paste page)

Process that divides the nucleus of a cell

Cell division that results in two identical diploid
“daughter” cells.
• Each daughter cell receives the exact same # and type of
chromosomes

Mitosis occurs for the purpose of:
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
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Reproduction (unicellular organisms only)
Growth and repair/maintenance of tissues
(multicellular organisms)
Consists of 4 phases:
• Prophase, Metaphase, Anaphase, and Telophase (PMAT)
• Followed directly by cytokinesis (divison of cytoplasm)
The Cell Cycle
Consists of:
•Interphase
•Mitosis/
Cytokinesis
Mitosis is a small
part of the cycle;
a cell spends
almost all of it’s
time in
interphase.
Most cells don’t continually go through the cell cycle; many stay in
interphase, without preparing to divide, for long periods (G0).
Instructions for taking notes

For each phase (interphase, prophase, etc.) copy the
information from the slide onto the cut & paste page.



If only certain phrases are bolded/underlined, copy
those.
If noting is bolded/underlined, copy it ALL.
Study the pictures provided of the phases. Label
certain structures on your cut & paste page (such as
centrioles, chromosomes, nucleus, etc.)

You don’t have to label these things in every picture.
But, be sure some pictures have labels.
Interphase
(write the description below on your cut & paste
page, under the first and last pictures)


NOT a “resting” phase for the cell. The cell
carries out normal metabolic processes (like
respiration, protein synthesis, etc.) and prepares for
cell division (if given signals that cell division is
needed).
Stages of interphase include:


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G1: Cell growth
S: DNA is replicated (copied)
G2: growth and preparations for cell division
Interphase (Plant)
cell wall
Notice that the
nucleus is clearly
visible (with a
nucleolus), but no
chromosomes are
visible.
The DNA is in the
invisible form of
chromatin.
Interphase (Animal)
Cell membrane
Nuclear membrane
Prophase: Mitosis Begins
(Copy the info below beneath the 2 pictures of prophase)
You have 2 pictures of prophase: an “early”
prophase and a “late” prophase. The picture
below is of “early” prophase. As prophase
proceeds the centrosomes would end up on
opposite poles and the chromosomes would be
distinct.
Centrosomes
(w/centrioles, if
it’s an animal
cell)
Watch the animation. Pause it when it
begins to talk about metaphase.
•Chromatin coils into
chromosomes (becomes
visible)
•Chromosomes consist of 2
chromatids
•Centrosomes migrate to
opposite sides of cell; spindle
fibers form and attach to
chromosomes
•Nuclear membrane dissolves
(disappears)
Animation: http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__mitosis_and_cytokinesis.html
Prophase (Plant)
Chromatin is condensing
into chromosomes. The
nuclear membrane is
dissolving.
Prophase (Animal)
Chromosomes
Metaphase Illustration
Centromere
Centrosome/
Centriole
*Chromosomes
consist of two
chromatids
Metaphase: Organizing the
Chromosomes
(Copy the info below beneath the picture of metaphase)
During metaphase, chromosomes
are pulled by spindle fibers to the
mid-line (“equator”) of the cell.
 They align “single file”.


Organizing the chromosomes before
separation will ensure that each new
cell will receive a full set of
chromosomes (genetic info).
Metaphase (Plant)
Chromosomes lined up along
the “equator” of the cell.
Metaphase (Animal)
Anaphase Illustration
(Copy the info below beneath the 2 pictures of anaphase)
In Anaphase:
Centriole
•Chromatids separate at
the centromere,
becoming individual
chromosomes
Spindle
Fibers
•Chromosome now = 1
chromatid
Chromatid
(now is also
called a
chromosome)
Centromere
•Spindle fibers shorten,
pulling chromatids to
opposite poles of cell
Watch the animation. Pause it when it
begins to talk about telophase.
Animation: http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__mitosis_and_cytokinesis.html
Anaphase (Plant)
Chromatids
Anaphase (Animal)
Centriole
Chromatids
Telophase Illustration
(Copy this under the picture of telophase.)
In telophase:
•Nuclear membrane forms
again; 2 nuclei are formed.
•Chromosomes uncoil into long
strands of chromatin
•Cytokinesis begins
Telophase (Plant)
Nuclear membrane forming
Cytokinesis
beginning to
seperate the 2
nuclei into 2
separate cells.
Chromatin
Telophase (Animal)
Cytokinesis
beginning to
seperate the 2
nuclei into 2
separate cells.
Nucleus
Cytokinesis Illustration
(Copy this under the picture of telophase.)
In cytokinesis:
•The cytoplasm divides
between the daughter cells
•Happens by cleavage
furrow (animal) or
formation of cell plate
(plant)
Cleavage
furrow
•Produces 2 daughter cells
Watch the remainder of the animation.
Animation: http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__mitosis_and_cytokinesis.html
Cytokinesis (Plant)
Cytokinesis (Animal)
Cleavage
Furrow
Quiz yourself!
Go to:
http://school.discoveryeducation.com/
quizzes6/muskopf/mitosis1.html
 On the back of your cut & paste page,
write your answers to the quiz
questions, in complete sentences.
