Cellular Growth
Chapter 9
Do Now
 1.
How big is a cell?
 2.
What happens if a cell gets too big?
DO NOW
Create a model of what happens
when you get a cut.
 Use
picture, words, symbols, etc.
 Be ready to present.
Objectives
 1.
SWBAT review what happens when you
get a cut.
 2. SWBAT calculate surface area to
volume ratio and relate it to the cell.
 3. SWBAT draw and label the cell cycle.
 4. SWBAT create 4 sample cells and
calculate out their surface area to volume
ratio and answer questions on it
9.1 Cellular Growth
 Ratio
Area
Volume
of Surface Area to Volume
Equations
 Surface Area:
 (2
x L x W) + (2 x L x H) + (2 x H x W)
 Area:
L
xWxH
Cell Size Limitations
 Key
factor that limits cell growth is ratio of
surface area to volume
 As
the cell grows, its volume increases
much more rapidly than the surface area.
 Cell
can have difficulty supplying nutrients
and expelling waste products.
Transport of Substances
 Plasma
Membrane: Substances move by
diffusion or by motor proteins.
 Diffusion over large distances is slow and
inefficient.
 Small cells maintain more efficient
transport systems.
Think – Pair - Share
 If



you had three cells:
3X2X2
6x1X1
3X6X1
 Which
cell has the largest surface area to
volume ratio?
 What benefit does this cell have?
Cellular Communications
 The
need for signaling proteins to move
throughout the cell also limits cell size.
 Cell
size affects the ability of the cell to
communicate instructions for cellular
functions.
DO NOW
 Surface
area : Volume :: _________ : _______
(Cell Parts)
Which cell has a bigger surface area to volume
ratio?
2x3x2
OR
4x1x1
What benefit does this cell have?
The Cell Cycle
 Cell
division prevents the cell from
becoming too large.
 It also is the way the cell reproduces so
that you grow and heal certain injuries.
 Cells reproduce by a cycle of growing and
dividing called the cell cycle
Cell Cycle
 Varies
between 8 minutes and one year
 Average 12-24 hours
Cell Cycle
1. Interphase (G1, S, G2)
2. Mitosis & Cytokinesis – Cell division
Do Now
 1.
Which stage of the cell cycle takes the
longest time?
 2.
Which stage of mitosis takes the longest
time?
 3.
Which stage of mitosis takes the least
amount of time?
Interphase
 A.


First growth phase
The cell is growing, carrying out normal cell
functions, and preparing to replicate DNA.
 B.



S Phase:
DNA is copied (DNA Replication)
 C.

G1 Phase:
G2 Phase:
Second Growth Phase
Proteins needed for cell division are produced
The cell prepares for the division of its nucleus.
Do Now
 List
three reasons why a cell divides.
Mitosis and Cytokinesis
 Mitosis:
Nuclear Division
 Cytokinesis: Cell Division
9.2 Mitotic Phase
(Cell Division)
 A.
Prophase
 B. Metaphase
 C. Anaphase
 D. Telophase

Label and
order the cells
from 1 – 5
 What are the
differences
between plant
and animal
cells during
division?
http://www.cellsalive.com/mitosis.htm
Chromosomes
Objectives
 1.
SWBAT draw and label the stages of
mitosis.
 2. SWBAT draw and label a chromosome.
 3. SWBAT practice labeling diagrams of
mitosis in partners.
Chromosomes

Chromosome

Chromatid

loosely coiled DNA
Centromere


Half a replicated Chromosome
Chromatin

Tightly coiled DNA
Center of a chromosomewhere the sister chromatids attach
Centriole

Organize the microtubules
Attach to the spindle fibers
Do Now – Label the Cell Cycle
Prophase
 The
cell’s chromatin tightens
 Sister chromatids are attached
at the centromere.
 Spindle fibers form in the
cytoplasm.
 The nuclear envelope seems to
disappear.
 Spindle fibers attach to the
sister chromatids.
Metaphase
 Sister
chromatids are pulled along the
spindle apparatus toward the center of the
cell.
 They line up in the middle of the cell.
Anaphase
 The
microtubules of the spindle apparatus
begin to shorten.
 The sister chromatids separate.
 The chromosomes move toward the poles
of the cell.
Telophase
 The
chromosomes arrive at the poles and
begin to relax.
 Two new nuclear membranes begin to
form and the nucleoli reappear.
 The spindle apparatus disassembles.
Cytokinesis
 In
animal cells, microfilaments constrict, or pinch,
the cytoplasm.
 In plant cells, a new structure, called a cell plate
forms.
Let’s review mitosis…
 http://highered.mcgraw-
hill.com/sites/0072437316/student_view0/
chapter11/animations.html
Think-pair-share
 Try
to label the parts of cell division.
Do Now – Label the Cell Cycle
Objectives
 1.
SWBAT identify cells in prophase,
metaphase, anaphase, telophase, and
cytokinesis
 2. SWBAT calculate the percent of time
each cell spends in each phase.
Do Now
 Label
the parts of the cell.
 What phases of mitosis?
Objectives
 1.
1. SWBAT brainstorm why cells have
check points.
 2. SWBAT create a list of their
preconceptions about cancer.
 3. SWBAT discuss treatments, causes,
and cancer.
 4. SWBAT compare and contrast the types
of stem cells and apply how they can be
useful in science.
9.3 Cell Cycle Regulation
 Normal


Cell Cycle:
Different cyclin / CDK (cyclin dependent
kinases) combinations signal other activities
These including
• DNA replication
• Protein synthesis
• Nuclear division
Quality Control Checkpoints
 The
cell cycle has built-in checkpoints
 These monitor the cycle and can stop it if
something goes wrong.
 Spindle checkpoints also have been
identified in mitosis.

Ex. If not spindle fibers – will stop before
cytokinesis
What can happen if there was a
mutation in the cell cycle?
Write down 5 things you know
about cancer.
 http://www.who.int/features/factfiles/cancer
/01_en.html
Abnormal Cell Cycle: Cancer
 Cancer
is the uncontrolled growth and
division of cells.
 Cancer cells can kill an organism by
crowding out normal cells, resulting in the
loss of tissue function.
Causes of Cancer
 Changes
that alter growth and division of
cells are due to mutations.
 Changes in DNA lead to changes in
____________.
 Carcinogen is a substance or agent that
is known to cause cancer
Types of Carcinogens

Tobacco
 Radiation (UV and X Rays)
 Asbestos

FDA regulates what you eat and drink is safe
and makes sure there are warning on
carcinogen products
Do Now
Explain the purpose of spindle checkpoints in the cell.
Objectives
 1.
SWBAT define apoptosis and stem
cells.
 2. SWBAT identify cells in prophase,
metaphase, anaphase, telophase, and
cytokinesis
 3. SWBAT calculate the percent of time
each cell spends in each phase.
Cancer Genetics
 Multiple
changes in DNA are needed to
cause cancer
 Cancer increase with age
 Certain cancers are inherited in certain
families (chances to have it)
Apoptosis
 Programmed
cell death
 Cells going through apoptosis actually
shrink and shrivel in a controlled process.




Ex. Leave in Fall
Ex. Webbed Fingers/Toes
DNA Damaged Cells
http://www.youtube.com/watch?v=qjjHKDn12q
I
Stem Cells
 Unspecialized
cells that can develop into
specialized cells when under the right
conditions
Stem Cells (Cont.)
Embryonic Stem Cells
Adult Stem Cells
After
Found
fertilization, the
resulting mass of cells
divides repeatedly until
there are about 100–150
cells.
in various tissues
in the body and might be
used to maintain and repair
the same kind of tissue
Less
These
cells have not
become specialized.
controversial
because the adult stem
cells can be obtained with
the consent of their donor
http://www.stemcellresearchfacts.com/definition.html
Video
 http://www.youtube.com/watch?v=27skh7p
rkN0&feature=related
Think – Pair - Share
 Why
do we care about stem cells?
 How
are they used in the field of scientific
research?
 As
tax payers in NJ, do we allocate our tax
money for this research?? (What do you
think?)
Quiz is on…

Cell Cycle









Interphase (G1, S, G2)
Mitosis (PMAT)
Cytokinesis
Phases of Mitosis
Cell Regulation (CDK, Checkpoints, and cyclins)
Cancer
Stem Cells
Apoptosis
Cell Volume VS. Surface Area Ratio
As a review….
 Draw
out the stages of mitosis using
colored pencils of a cell with 6
chromosomes.