Mitosis
Mitosis Essential Questions
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•
•
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How do somatic cells reproduce?
What is the purpose of mitosis?
What are the names of the phases of mitosis?
How do interphase and cytokinesis relate to
mitosis?
• What happens in each of the four phases of
mitosis?
Mitosis: the process by which a somatic cell replicates
itself
-The purpose of mitosis is to produce two daughter
cells which are identical to the parent cell
Somatic cell
reproduction
• Interphase
• Phases of mitosis
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Prophase
Metaphase
Anaphase
Telophase
• Cytokinesis
Interphase takes place before mitosis starts.
Interphase:
The cell grows
The cell duplicates its DNA
Before Mitosis:
Interphase:
The cell grows
The cell duplicates its DNA
Chromatin
(A piece of DNA before it’s duplicated)
Normal nucleus with
two pieces of chromatin
Phases of Mitosis:
Before Mitosis:
Interphase:
The cell grows
The cell duplicates its DNA
Chromatin
(A piece of DNA before it’s condensed and duplicated)
Normal nucleus with
two pieces of chromatin
Nucleus with condensed,
duplicated DNA
1. Chromosome: the entire
duplicated, condensed
chromatin
*DNA is duplicated in
interphase but not
condensed until prophase
2. Chromatid: one of the
two identical copies of DNA
that makes up the
chromosome
Nucleus with duplicated DNA
3. Centromere: holds together
two sister chromatids
Somatic cell
reproduction
• Interphase
• Phases of mitosis
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–
–
–
Prophase
Metaphase
Anaphase
Telophase
• Cytokinesis
The division of the
cytoplasm
P. 257: 1-7
1. Certain cyclin proteins regulate mitosis and the
cell cycle by allowing or stopping cell cycle
processes.
2. It is shorter; cancer cells divide in an
unrestrained way.
3. Cigarette smoke, UV radiation, asbestos, etc.
4. In apoptosis, a cell undergoes programmed cell
death; cancer cells can grow and divide
unrestrained as long as they are supplied with
essential nutrients.
P. 257: 1-7
5. Stem cells can be used to cure diseases.
6. Embryonic stem cells are found in living
human embryos; adult stem cells are found in
already developed tissues.
7.The DNA damage would cause the cell to be
unable to perform its correct function.
Somatic cell
reproduction
• Interphase
• Phases of mitosis
–
–
–
–
Prophase
Metaphase
Anaphase
Telophase
• Cytokinesis
Before Mitosis:
Interphase:
Phases of Mitosis:
1. Prophase:
Chromatin is
condensed into
chromosomes
Nuclear
membrane
disappears
Before Mitosis:
Interphase:
Phases of Mitosis:
1. Prophase
2. Metaphase
Chromosomes line up
along the middle of the cell
Spindle fibers form
between centromeres and
centrioles
-Spindle fibers: rope like
structures that separate
sister chromatids
-Centriole: the organelle from
which spindle fibers develop
Before Mitosis:
Interphase:
Phases of Mitosis:
1. Prophase
2. Metaphase
Chromosomes line up
along the middle of the cell
Spindle fibers form
between centromeres and
centrioles
Before Mitosis:
Interphase:
Phases of Mitosis:
1. Prophase
2. Metaphase
3. Anaphase
Sister chromatids
are pulled to
opposite sides of
the cell
Before Mitosis:
Interphase:
Phases of Mitosis:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
A new nuclear membrane
forms around the
chromosomes at each end
of the cell
Chromosomes expand
back into chromatin
Before Mitosis:
Interphase:
Phases of Mitosis:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
Before Mitosis:
Interphase:
Phases of Mitosis:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
-The term “mitosis” technically involves only the
division of the cell’s nucleus
After mitosis:
-Cytokinesis: the division of the cell’s cytoplasm
What is Cytokinesis
• This Is the last stage of the cell cycle &
it completes the process of cell division.
• During Cytokinesis the cytoplasm
divides and organelles are distributed
into each of the new cells.
Cytokinesis in animal cells
• During cytokinesis in animal cells the cell
membrane squeezes together around the
middle of the cell
• Each daughter cell gets about 1/2 of the
organelles.
Cytokinesis in plant cells
• The plant cell t can’t squeeze together like the
cell membrane can.
• Instead a structure called the cell plate forms
across the middle of the cell and the cell
gradually splits into two cells.
• Then two new cell walls form
More info
• When cytokinesis is complete two new
cells (daughter cells) have formed.
• At the end of cytokinesis each cell enters
interphase and the cell cycle begins.
Cytokinesis in a animal cell.
The arrow’s point out the cell membrane seperating
Mitosis Flip Book
Today, you will begin working on your mitosis animation flip book.
Interphase correctly drawn
Interphase correctly annotated
Prophase correctly drawn
Prophase correctly annotated
Metaphase correctly drawn
Metaphase correctly annotated
Anaphase correctly drawn
Anaphase correctly annotated
Telophase correctly drawn
Telophase correctly annotated
Cytokinesis correctly drawn
Cytokinesis correctly annotated
Color included
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Effort
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Title page
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Mitosis Essential Questions
•
•
•
•
How do somatic cells reproduce?
What is the purpose of mitosis?
What are the names of the phases of mitosis?
How do interphase and cytokinesis relate to
mitosis?
• What happens in each of the four phases of
mitosis?
Mitosis Essential Questions
• How do somatic cells reproduce?
Through the process of mitosis
• What is the purpose of mitosis?
To make daughter cells that are identical to the parent
cell
• What are the names of the phases of mitosis?
Prophase, Metaphase, Anaphase, Telophase
• How do interphase and cytokinesis relate to mitosis?
They are not a part of mitosis. Interphase happens
before mitosis; cytokinesis happens after.
• Prophase
Phases of Mitosis
– Chromatin is condensed into chromosomes
– Nuclear membrane disappears
• Metaphase
– Chromosomes line up along the middle of the cell
– Spindle fibers form between centromeres and
centrioles
• Anaphase
– Sister chromatids are pulled to opposite sides of the
cell
• Telophase
– A new nuclear membrane forms around the
chromosomes at each end of the cell
– Chromosomes expand back into chromatin