Chapter 10 Dragonfly
Cell Growth and
Division
Standards Addressed
National
• 7 1.e Students know cells divide to increase their
numbers through a process of mitosis,which results in
two daughter cells with identical sets of chromosomes
• 6IIE 7.c Construct appropriate graphs from data and
develop qualitative statements about the relationships
between variables
• 6IIE 7.e Recognize whether evidence is consistent with
a proposed explanation
State
• BIIE 1.g Recognize the usefulness and limitations of
models and theories as scientific representations of
reality.
Section 10-1 Cell Growth
Key Concept: What problems does growth cause for cells?
I. Limits to cell growth
1. Why do cells divide rather than continue to grow indefinitely?
a.
The ___________
the cell is the more demands are
larger
placed on the cell’s _____
DNA
b.
Its more difficult to move enough ____________
nutrients and
___________
across the cell membrane
wastes
2. “DNA Overload”:
a. DNA controls_____
cell __________
function ; found in
nucleus of eukaryotes
b. DNA meets the needs of the cell when the cell is_________,
small
however as the cell increases in size, the DNA cannot meet its
needs anymore  “______________
crisis
Information _________”
3. Exchanging Materials:
a. ________,
_________,
and _______
Food
oxygen
water
enter a cell through its cell membrane.
b. ________
Waste _________
products leave the same
way.
c. Rate of this exchange depends on the
surface area to volume ratio
II. Surface Area to Volume Ratio
1. To obtain the ratio of surface area to volume,
__________
the surface area by the volume.
divide
Cell Sizes
Surface Area
lengthxwidthx6
Volume
Lengthxwidthxheight
Ratio of surface
area to volume
6 cm2
24
54 cm2
cm2
27cm3
1 cm3
6:1
8 cm3
3:1
2:1
Notice that volume _____________
much
increases
more rapidly than surface area.
This causes the ______________________
surface area to volume
ratio to decrease
_________________,
which is a serious
problem for the cell.
As cells get _____
large
it makes it more
too _________
difficult to get sufficient amounts of oxygen and
nutrients in and waste products out.
Question: How does an organism get bigger if
the cells that it is made of do not get larger?
It grows more cells.
Answer: _____________________
III. Division of the Cell
1. Before the cell gets too large it divides into
two “_____________”
cells
daughter
2. The process is called ________
cell
_______________.
division
Cell division solves the problem of cells
getting too large
by _______________
while
Increasing
size
__________________
(more small cells
reducing volume
instead of one large cell)
3. Before cell division, the cell ____________,
replicates
or copies, its entire DNA.
a. This solves the problem of
information storage because each
___________________
daughter cell gets a complete set of
__________
genetic information
4. Each cell has an increase in ratio of surface
area to volume that allows for more efficient
__________________
exchange
of materials with the environment.
10-2 Cell Division
Key Concepts: What are the main events of the cell cycle?
What are the four phases of mitosis?
All cell division must involve the replication of DNA
before cell division so the genetic information can be
transferred to the daughter cells.
In Prokaryotes the rest of cell division is simply to
divide
the contents
__________________.
In Eukaryotes the division is more complex it
occurs in two stages:
division of the nucleus
a.
Mitosis: ________________________
b.
___________: division of the cytoplasm
Cytokinesis
Unicellular organisms use mitosis and
cytokinesis to ________________.
reproduce
This is a type of _______________
asexual
reproduction producing two identical daughter
cells from ______
identical parent cell.
one
Multicellular organisms use mitosis and
add new cells to the organism
cytokinesis to _________________________
____________________________
for
growth and development
I. Chromosomes
1. Chromosomes are composed areDNA
______
and __________
(histones) and carry the
proteins
genetic information in eukaryotic cells.
a. Each species of organism has a
_________
specific ________
number of chromosomes.
1. Drosophila melanogaster has 8
___
chromosomes
2. Humans have 46
____ chromosomes
b. Chromosome are not
____ __________
visible
except during cell division. (known
as
chromatin
___________ when not dividing)
c. Replication (copying) of the DNA occurred
_______________________
therefore every
before cell division
chromosome is actually two identical “______”
sister
chromatids
d. Each pair of chromatids is connected to
each other at an area called the
___________,
centromere usually located near the center
of the chromosome.
centromere
Sister
chromatids
http://www.biostudio.com/demo_freeman_dna_coiling.htm
I. The Cell Cycle
1.Cell Cycle: the series of events the cell
goes through as they
grow________________
and divide
separated by periods of “in-between” time
called ___________.
interphase
grows
2. During the cell cycle the cell ________,
prepares for __________,
division and divides to form
two daughter cells, each of which then
begins the cycle again
__________________________.
3. Four
_______ phases of the cell cycle
I. Events of the Cell Cycle
a. G1 phase:cell
__________,
increase in size
growth
and ______________
new proteins and
synthesize
organelles.
b. S phase: chromosome replication
__________
(synthesis)
c. G2 phase: shortest of the phases,
organelles and molecules required for
cell division are produced.
___________
d. M Phase:mitosis
_________and cytokinesis
____________
G1, S, and G2 are all taking place during
____________
interphase : the phase between
divisions.
G1
M-phase
s
G2
I. Mitosis
a. The mitotic phase can be sub-divided into
four phases ______________,
prophase
_____________,
and
anaphase
metaphase _____________
_____________
(PMAT).
telophase
b. Mitosis is strictly _____________
division.
nuclear
c. Mitosis is followed by cytoplasmic division,
or
cytokinesis
___________, to complete cell division
d. Mitosis results in two “daughter cells”,
identical to each other, and is
which are ________
used for growth and asexual reproduction.
e. The growth and synthesis phases are
collectively called interphase (i.e. in
between cell division).
f. The only source of genetic variation in the
cells is via ________________.
mutations
Interphase
Stage
between
division
 This is when the cell is
not dividing, but is carrying
out its
normal cellular functions
____________________.
not visible
 Chromatinis_____
 DNA
_____, histones and
centrioles all replicated
 Replication of
______________
cell organelles e.g.
mitochondria, occurs in the
cytoplasm.
 G1, S and G2 phases are
occurring
Prophase
Beginning
of mitosis
(nuclear
division)
 chromosomes ___________
and become ___________.
condense
 Due to DNA replication
visible
during interphase, each
chromosome consists of two
identical sister
______________
chromatids connected at
the ____________
centromere
 centrioles move to opposite
_________ poles of cell (in
animal cells) disappears
 Nucleolus ______________
 Spindle fibers (microtubules)
begin
to form and
attach
___________ to chromosomes
near the centromere
 Phase ends with the
breakdown
of the
nuclear envelope
_________________
Metaphase
(middle)
Anaphase
chromosome
separate
Spindle fibers
(microtubules) connect
centrioles
______________
to
chromosomes
Chromosomes align
equator
along
___________of cell.
Centromeres _______,
split
allowing sister chromatids
to ________________
separate
Chromatids move towards
opposite
__________
poles, centromeres first,
creating a “V” shape
Telophase
New
nuclei form
Spindle fibers
____________
_________________
disperse
_
Nuclear membrane
form around each set
of chromatids
Nucleoli
reform
___________
End of nuclear
division
F.Y.I.: Asexual reproduction is the production of
offspring from a single parent using mitosis. The
offspring are therefore genetically identical to each
other and to their “parent”- in other words they are
clones. Asexual reproduction is very common in
nature, and in addition we humans have developed
some new, artificial methods. The Latin terms in vivo
(“in life”, i.e. in a living organism) and in vitro (“in
glass”, i.e. in a test tube) are often used to describe
natural and artificial techniques.
Centrioles
Centrioles
Centromere
Nuclear
envelope
Daughter
Cells
Chromatin
Centrioles
Chromosomes
_______________
(paired chromatids)
Spindle
Centrioles
Individual
Chromosomes
Nuclear
envelope
reforms
http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter11/animations.html#
Mitosis Virtual Lab
• http://district.bluegrass.kctcs.edu/billd.snyd
er/sharedfiles/biowebsite/BiologyLabs/BIO
137/137Lab2/Lab2MitosisSlides.html
Onion Root Tip
For Use with Lab:
Plant Cell Growth as seen in Onion Root Tip
Animal Cell Division in White Fish Blastula
Cytokinesis
Cytoplasmic
division
New
daughter
cells form
In animal cells a
_______________
cleavage furrow forms,
which splits the cell in two.
In plant cells vesicles
move to the equator, line
up and fuse to form two
membranes called the
__________.
A new
cell plate
_________
cell wall is laid down
between the membranes,
which fuses with the
existing cell wall.
V. Cytokinesis:
a. Division of the ________________
cytoplasm
b. End of the ____
cell _________
cycle
c. Production of two ______________
daughter cells
identical
plants
d. Different in _________
and _________
cells
animals
Cell plate
forming
Wall of
parent cell
Daughter
nucleus
Cleavage
furrow
Cleavage
furrow
Contracting ring of
microfilaments
Daughter cells
Cell wall
Vesicles containing
cell wall material
New cell wall
Cell plate
Daughter
cells
10-3 Regulating the Cell Cycle
Key Concepts: How is the cell cycle regulated?
How are cancer cells different from other
cells?
______________
organisms control cell growth
Multicellular
and division very carefully (way to increase
number of cells and size of organism)
F.Y.I. In different cell types the cell cycle can last
from hours to years. For example bacterial cells
can divide every 20-30 minutes under suitable
conditions, skin cells divide about every 12 hours
on average, liver cells every 2 years, brain and
muscle cells do not divide.
This provides the _______________
of cells
replacement
that ________________________.
wear out or are broken down
I. Controls on Cell Division:
1. Cells in a ________________
will continue to divide
petri dish
until they come into ___________
with other cells.
contact
2. Then the cells ________
stop _____________
dividing
3. Cells are ______________
from the center of the
removed
dish.
4. Then the cells _______________
the open space
bordering
will begin dividing.
5. Until they have _______
the empty space.
filled
6. The controls for cell growth and division can be
___________________.
turned on and off
7. We can see the same thing happen in our
__________________.
own bodies
3.
1.
5.
2.
4.
Question: What happens when you cut your finger or
break your bone?
Answer: The cells bordering the injury will begin
dividing to fill in the gap in the tissues that
have been torn or broken. This is the process
known as healing.
II. Cell Cycle Regulators
1. Scientists wondered what ____________cell
controlled
division.
2. Tim Hunt and Mark Kirschner discovered
that cells in mitosis contained a protein that
when injected into a cell would cause the
formation of spindle fibers.
3. Protein group known as ____________
cyclins
regulates the cell cycle.
4. They rise and fall in time with the ________.
cell cycle
5. Cyclins _____________
the timing of the
regulate
cell cycle in __________cells.
eukaryotic
a. Two main groups of protein
regulators
b. Internal Regulators: respond to
inside the cell
events __________________
.
Ex. Make sure cell doesn’t enter
mitosis until chromosomes have all
replicated
c. External Regulators: respond to
events _________________________.
outside the cell
Ex. Embryonic growth and healing
III. Uncontrolled Cell Growth
A. Cancer
1. Cell Growth is so controlled because when it
is not controlled things go very, very______.
wrong
2. _________
is a disorder in which some of
Cancer
the body’s own cells lose the ability to
control growth.
3. Cancer cells do not respond to the
_____________that
regulate the growth of
signals
most cells.
4. When cells divide ___________________
uncontrollable
they form masses of cells called __________
tumors
that can damage the surrounding tissue.
5. Cancer cells can break off and
_____________
throughout the body
spread
disrupting normal activities and causing
serious medical problems or even death.
B. Causes of Cancer
1. Smoking ____________
tobacco
2. _____________
exposure
Radiation
Viral Infection
3. ______________
4.____________
defect in gene p53
Genetic
C. Cancer is a disease of the __________.
cell cycle
http://www.gardasil.com/
Breast Cancer Cell