Warm Up-Cell Division
• K-W-L: Cell Division
Warm Up-Cell Cycle
1. Write “The Cell Cycle”
2. List the four phases of
mitosis and their key word.
ACOS 5 & 9
• SWBAT discuss “The Cell
Cycle”.
Mitosis Drawing
• Page 98-99
• Draw & label everything
except the pinkish-purple
circles.
Cell Division and Mitosis
1
• Cell division allows growth, replaces worn
out or damaged cells, and sometimes
produces an entire new organism.
Cell Division and Mitosis
1
• Multicellular organisms grow because cell
division increases the total number of cells in
an organism.
• Unicellular organisms reproduce an entire new
organism by cell division.
Cell Division and Mitosis
1
Length of Cycle
• The cell cycle is a series of events that takes
place from one cell division to the next.
• Cell Cycle
• Interphase
• Mitosis
• Cytokinesis
Cell Division and Mitosis
1
Interphase
• Interphase is the time during the cell cycle
between cell division.
• During interphase a copy of the hereditary
material must be made so that each of the two
new cells will get a complete copy but no
division takes place.
Cell Division and Mitosis
1
• A chromosome is a structure in the nucleus
which contains hereditary material that
duplicates during interphase.
Cell Division and Mitosis
1
Interphase
• After interphase, cell division
begins.
Cell Division and Mitosis
1
• When the nucleus is ready to divide, each
duplicated chromosome coils tightly into two
thickened, identical
strands called chromatids.
Cell Division and Mitosis
1
Mitosis
• Mitosis is the process in which
the nucleus divides to form two
identical nuclei.
Cell Division and Mitosis
1
Mitosis
• The phases of mitosis in order
are:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
Cell Division and Mitosis
1
• Prophase = Prepare
• Prophase is when the
nucleus prepares to
divide.
• Two small structures
called centrioles move to
opposite ends of the cell.
• Between the centrioles,
threadlike spindle fibers
begin to stretch across the
cell.
Cell Division and Mitosis
1
• Metaphase = Middle
• Metaphase is when the pairs of chromatids
line up across the middle of the cell.
• The centromere of
each pair usually
becomes attached to
two spindle fibers,
one from each side
of the cell.
Cell Division and Mitosis
1
• Anaphase = Apart
• During anaphase the
spindle fibers shorten
and each pair of
chromatids begin to
move apart.
• The separated
chromatids are now
called chromosomes.
Cell Division and Mitosis
1
Telophase = Two
• During
telophase the
spindle fibers
start to
disappear, the
chromosomes
start to uncoil,
and two nuclei
form.
Cell Division and Mitosis
1
Cytokinesis
• Cytokinesis is when the cell membrane
pinches in the middle and the cytoplasm
divides.
• After the nucleus has divided, the cytoplasm
separates and two new cells are formed.
• Following cytokinesis new cells begin
interphase again.