Transcript Ch. 10 Flip Book

Mitosis
The Cell Growth & Division
Page 1:
 Limits to Cell Growth- 2 main
reasons cells divide rather than continuing to
grow indefinitely:
–More Demands on DNA When cell increases in size it does not
make extra copies of DNA
 If cell grew without limits “information
crisis” would occur.
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–Exchanging MaterialsFood, oxygen, & water have to enter
the cell through the cell membrane
Waste products have to leave
The rate at which this exchange
takes place depends on the surface
area of the cell (total area of the cell
membrane)
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
Ratio of Surface Area to Volume
– Volume increases more rapidly than the surface area
– Therefore, ratio of surface area to volume decreases
This decrease causes serious problems for the cell
– If too large becomes to difficult to get enough oxygen
and nutrients in and wastes out
This is why cells do not grow much bigger even if the
organism of which they are a part of does.
Quick Lab (p. 242) Analyze & conclude 1-2
Page 2
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Define from the chapter:
Cell Division
Mitosis
Chromosome
Chromatid
Draw a picture of chromosome & Chromatid
Centromere
Cell cycle
Spindle fibers
Centrioles
Draw a picture of Centrioles & Spindle fibers
Page 3
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Cell Growth
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Describe:
 G1- period of activity in which cells do
most of their growing. Cells increase in
size and synthesize new proteins and
organelles
 S- Chromosomes are replicated and
synthesis of DNA molecules takes place
 G2- Many organelles and molecules
required for cell divisions are produced
 M phase- Mitosis
Add Color!
– Interphase
 G1 phase (gap) growth
& metabolic activity
 S phase (DNA
replication)
 G2 phase (gap) cells
prepares for division
– Mitosis
– Cytokinesis
(cytoplasmic division)
Page 4
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Draw, label, & describe the phases of:
Interphase
 Prophase
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Add Color!
Page 5
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Draw, label, & describe the phases of:
Metaphase
 Anaphase
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Add Color!
Page 6
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Draw, label, & describe the phases of:
–Telophase
–Cytokinesis- for both plant & animal
Add Color!
A Cell’s Appearance During
Interphase
Plasma membrane
Nucleoplasm
Cytoplasm
Nuclear
envelope
Prophase
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Replicated chromosomes,
which are being held together
by a centromere, condense.
Centrioles move to opposite
poles of the cell.
Nuclear envelope and
nucleolus disperse.
Microtubules are assembled
from tubulin proteins in the
cytoplasm, and these
structures associate with the
centrioles and the
chromosomes.
A spindle-shaped array of
microtubules (spindle fibers)
forms between the centrioles
as they move apart.
Metaphase
The doubled
chromosomes
become attached
to the spindle
fibers by their
centromeres.
 The chromosomes
begin to line up on
the midline
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Anaphase
The centromers
split apart and
chromatid pairs
from each
chromosome
separate from each
other
 The chromatids are
pulled apart by the
shortening of the
microtubules in the
spindle fibers.

Telophase
The chromatids
reach the opposite
poles of the cell.
 The spindle breaks
down, the
nucleolus
reappears, & a
new nuclear
envelope forms
around each set of
chromosomes.
 A new double
membrane begins
to form between
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Cytokinesis
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Animal Cells- the plasma
membrane pinches in along the
equator and 2 new cells are
separated.
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Plant Cells- Have a rigid cell
wall, so the plasma membrane
does not pinch in.
The cell plate is laid down
across the cell equator.
A cell membrane forms around
each cell, & new cell calls form
on each side of the cell plate
until separation is complete.
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Mitosis Animation
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Mitosis Animation
A
B
C
D
E
F
G
H
I
Now,
name
and
then
order
these
phases
of
mitosis
.
Page 7
Regulating the Cell Cycle:
Cell cycle regulators–
early 1980’s biologists found a protein that
increased & decreased the time with the cell
cycle
– They called it cyclin because it seemed to
regulate the timing of the cell cycle
– Since, they have discovered a whole family of
cyclin proteins
Page 7 Continued
Two types of Regulator Proteins
1. Internal Regulators- proteins that respond to
events inside the cell
–
–
2.
Allows cell cycle to proceed only when certain
processes have occurred inside the cell
Ex: doesn’t let the cell enter mitosis until all
chromosomes have been replicated
External Regulators- Proteins respond to events
outside the cell
–
–
Direct cells to speed up or slow down cell
Ex: Growth factors- stimulate growth & cycle division of
cells. Important in embryonic cells & wound healing
Page 8
Uncontrolled Cell Growth
Cancer- disorder in which some of the
body’s own cells lose the ability to control
growth.
Cancer cells do not respond to the signals
that regulate the growth of most cells,
they divide uncontrollably & form masses
of cells called tumors that can damage
surrounding tissue.
Page 8 Continued
Two types of tumors:
1. Benign- does not spread to surrounding
tissue (non cancerous)
2. Malignant- Spreads & destroys healthy
tissue (cancerous)
Causes:
1. Biological Agent- viruses
2. Chemical Agent- carcinogens- tobacco
3. Physical Agent- radiation
4. Genetics
Page 8 Continued
Treatments:
1. Surgery
2. Radiation
3. Chemotherapy
The End
Onion Root Tip

Under Low Power…

Look for this 1st then
SWITCH TO HIGH
POWER!!!!!
Onion Root Tip

Identify the
stages
Onion Root Tip
Page 9
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DNA Scientists Chart
Pg. 10
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DNA NOTES
Pg. 11
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DNA REPLICATION