Transcript Cellular Reproduction

Cellular Reproduction
Section 1: Cellular Growth
Section 2: Mitosis and Cytokinesis
Section 3: Cell Cycle Regulation
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Recap: What are the 3 components of the cell
theory??
1. All living organisms have one or
more cells.
2. Cells are the basic unit of
structure and function.
3. All cells come from preexisting
cells.
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• Section 1: Cellular Growth
– Introduction:
• Since all living organisms are made of cells,
the only way an organism can grow or heal
itself is by cellular reproduction.
• Cell sizes must be limited to ensure that the
needs of the cells are met.
– Most cells are smaller than the period on the end
of this sentence. !!! WHY ARE THEY SO
SMALL???...
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• Section 1: Cell Growth
• I. Cell Size Limitations:
1. Surface area to volume ratio
• A. Surface Area= all of the area available for reactions
to occur (covered by the plasma membrane….)
– Formula= length x width x # of sides
B. Volume= space inside (includes organelles and
cytoplasm…)
– Formula= length x width x height
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Section 1
Cellular Reproduction
Cellular Growth
Ratio of Surface Area to Volume
Cellular Growth
• Is bigger better??
– No!! Small cells transport substances more
efficiently.
– Surface area to volume ratio decreases as the cell
grows larger.
Section 1
Cellular Reproduction
Cellular Growth
-As the cell grows, its volume increases
much more rapidly than the surface
area.
-The cell might have difficulty supplying
nutrients and expelling enough waste
products.
Cellular Growth
Cell Size Limitations continued…
• 2. Transport of substances- limits cellsize
because small cells can transport easier.
– Think Selective permeability! Once inside,
substances move by diffusion and proteins
• Slow in large cells because more space to travel
Section 1
Cellular Reproduction
Cellular Growth
3. 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.
Section 1
Cellular Reproduction
Cellular Growth
II. The Cell Cycle
-Eukaryotic cells
-Somatic Cells (all body cells EXCEPT sex
cells)
-Cycle produces genetically identical cells
(to parent cell).
Cellular Growth
• *Once a cell reaches its size limit, it must either stop
growing or divide!
• Division = Reproduction
• **Reproduction allows you to grow and heal certain
injuries!
• Cell cycle=each time a cell goes through a complete
cycle, it becomes 2 cells. Repeats cause continuous
production of new cells.
Cellular Growth
Stages of the Cell Cycle
Cellular Growth
• 3 Main Stages: (each can be subdivided)
– 1. Interphase= *Majority of a cells life; cell grows,
carries out all cell functions, and replicates DNA;
(3 sub stages).
– 2. Mitosis= cell nucleus and nuclear material
divide (4 sub stages).
– 3. Cytokinesis= cytoplasm divides creating a new
cell. *shortest time spent here
– Cell Cycle duration varies depending on the cell type;
Most animal cells around 12-24hrs.
Section 1
Cellular Reproduction
Cellular Growth
Digging Deeper…
A. The Stages of Interphase
The first stage of interphase, G1 (Gap 1)
 *Immediately after a cell divides.
 Function: growing, normal cell function, prepares to
replicate DNA.
 Side note: muscle and nerve cells exit after this step, brain
damage is permanent!
Section 1
Cellular Reproduction
Cellular Growth
The Second Stage of Interphase, S
(synthesis)
Function: cell copies its DNA (prepares for division)
*Chromosomes contain DNA (housed in nucleus)
Section 1
Cellular Reproduction
Cellular Growth
The Third Stage of Interphase, G2 (Gap 2)
*Follows S
*Function: cell nucleus prepares to divide and inventory
taken to ensure mitosis can proceed.
Cellular Growth
• B. The stages of Mitosis
– Prophase, Metaphase, Anaphase, Telophase
• Differ by: appearance and chromosome location
• Follows S phase of interphase
• Function: cells nuclear material (chromosomes) divide
and separate to opposite ends of the cell.
Cellular Growth
• C. Cytokinesis
– *Follows mitosis
– *Function: cell splits/divides
– Product*= 2 “daughter cells” with identical nuclei!!
Cellular Growth
• Prokaryotic cells differ…
– Why?? They are simple cells!
– Use binary fission-a form of asexual reproduction
to reproduce (similar to cloning)
– Homework: page 247 1-4; 6
Chapter
Cellular Reproduction
Section 1 Formative
Questions
Which can more efficiently supply nutrients and
expel waste products?
A. larger cells
B. smaller cells
C. cells with lower surface area to volume
ratio
1.
A
D. cells shaped like a cube
2.
3.
4.
B
C
D
Chapter
Cellular Reproduction
Section 1 Formative
Questions
At what stage does a cell spend most of
its life?
A. cytokinesis
B. interphase
C. mitosis
D. synthesis
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Section 1 Formative
Questions
What happens in the cell during cytokinesis?
A. The cell grows and carries out normal
functions.
B. The cell copies its DNA and forms
chromosomes.
1.
A
C. The cell’s nucleus and nuclear material
2.
B
divide.
3.
C
D. The cell’s cytoplasm divides.
4.
D
Section 2
Cellular Reproduction
Mitosis and Cytokinesis
The Stages of Mitosis
 Prophase
 The cell’s chromatin tightens.
 Sister chromatids are attached at the
centromere.
 Spindle fibers form in the cytoplasm.
Section 2
Cellular Reproduction
Mitosis and Cytokinesis
 The nuclear
envelope seems
to disappear.
 Spindle fibers
attach to the sister
chromatids.
Section 2
Cellular Reproduction
Mitosis and Cytokinesis
Metaphase
 Sister chromatids
are pulled along the
spindle apparatus
toward the center of
the cell.
 They line up in the
middle of the cell.
Section 2
Cellular Reproduction
Mitosis and Cytokinesis
Anaphase
 The microtubules of the spindle apparatus
begin to shorten.
 The sister chromatids separate.
 The chromosomes move toward the poles
of the cell.
Section 2
Cellular Reproduction
Mitosis and Cytokinesis
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.
Section 2
Cellular Reproduction
Mitosis and Cytokinesis
Cytokinesis
 In animal cells, microfilaments constrict, or
pinch, the cytoplasm.
 In plant cells, a new structure, called a cell
plate, forms.
Chapter
Cellular Reproduction
Section 2 Formative
Questions
In what stage of the cell cycle does the
cell’s replicated genetic material separate?
A. cytokinesis
B. interphase
C. mitosis
D. prophase
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Section 2 Formative
Questions
Which diagram shows anaphase?
A.
C.
B.
D.
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Section 2 Formative
Questions
At the end of mitosis the nuclear material is
divided and two new cells have formed.
A. true
B. false
1. A
2. B
Section 3
Cellular Reproduction
Cell Cycle Regulation
I. Normal Cell Cycle
 Check points in place
 Different cyclin/CDK
combinations signal
other activities,
including DNA
replication, protein
synthesis, and nuclear
division throughout the
cell cycle.
Section 3
Cellular Reproduction
Cell Cycle Regulation
Quality Control Checkpoints
 The cell cycle has built-in checkpoints that
monitor the cycle and can stop it if something
goes wrong.
 Spindle checkpoints also have been identified
in mitosis.
Section 3
Cellular Reproduction
Cell Cycle Regulation
II. Abnormal Cell Cycle: Cancer
 A. 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.
Section 3
Cellular Reproduction
Cell Cycle Regulation
B. Causes of Cancer
 The changes that occur in the regulation of
cell growth and division of cancer cells are
due to mutations.
 Various environmental factors can affect the
occurrence of cancer cells.
Section 3
Cellular Reproduction
Cell Cycle Regulation
III. Apoptosis
 Programmed cell death
 Cells going through apoptosis actually shrink
and shrivel in a controlled process.
Section 3
Cellular Reproduction
Cell Cycle Regulation
IV. Stem Cells
 Unspecialized cells
that can develop into
specialized cells
when under the right
conditions
Section 3
Cellular Reproduction
Cell Cycle Regulation
A. Embryonic Stem Cells
 After fertilization, the resulting mass of cells
divides repeatedly until there are about
100–150 cells. These cells have not become
specialized.
Section 3
Cellular Reproduction
Cell Cycle Regulation
B. Adult Stem Cells
 Found in various tissues in the body and
might be used to maintain and repair the
same kind of tissue
 Less controversial because the adult stem
cells can be obtained with the consent of
their donor
Cellular Reproduction
Chapter
Cellular Reproduction
Section 3 Formative
Questions
What are the “key and ignition” that start the
various activities in the cell cycle?
A. chromatin and chromosomes
B. cyclin and CDKs
C. microtubules and spindle fibers
D. protein and ribosomes
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Section 3 Formative
Questions
Which of these cancer-causing substances or
agents is impossible to avoid completely?
A. chemicals such as asbestos
B. food and drinks that the FDA warns may
contain carcinogens
C. tobacco and second-hand smoke 1. A
2.
B
D. ultraviolet radiation from the Sun 3. C
4.
D
Chapter
Cellular Reproduction
Section 3 Formative
Questions
What is the term for the programmed death
of cells that are damaged beyond repair or
have harmful changes in their DNA?
A. apoptosis
B. carcinogens
C. cytokinesis
D. mitosis
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Section 3 Formative
Questions
Which cells are not locked into becoming
one particular kind of cell and are capable
of developing into specialized tissues?
A. apoptotic cells
B. cancer cells
C. prokaryotic cells
D. stem cells
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Chapter Resource Menu
Chapter Diagnostic Questions
Formative Test Questions
Chapter Assessment Questions
Standardized Test Practice
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Animation
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Chapter
Cellular Reproduction
Chapter Diagnostic
Questions
Which is the first phase of mitosis?
A. interphase
B. prophase
C. metaphase
D. telophase
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Chapter Diagnostic
Questions
During what phase do the sister chromatids
line up in the middle of the cell?
A. interphase
B. metaphase
C. anaphase
D. telophase
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Chapter Diagnostic
Questions
Which is not a phase of the cell cycle?
A. cytokinesis
B. interphase
C. apoptosis
D. mitosis
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Chapter Assessment
Questions
This cell has completed
what stage of mitosis?
A. anaphase
B. interphase
C. metaphase
D. telophase
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Chapter Assessment
Questions
What term is used to describe programmed
cell death?
A. apoptosis
B. anaphase
C. necrosis
D. cyclins
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Chapter Assessment
Questions
What is the role of cyclins in a cell?
A. to control the movement of microtubules
B. to signal for the cell to divide
C. to stimulate the breakdown of the nuclear
membrane
1.
A
D. to cause the nucleolus to disappear
2.
3.
4.
B
C
D
Chapter
Cellular Reproduction
Standardized Test
Practice
Which cell has the lowest ratio of surface area
to volume?
C
A
B
1.
2.
3.
A
B
C
Chapter
Cellular Reproduction
Standardized Test
Practice
At what stage of interphase
does the cell take inventory
and make sure it is ready for
the division of its nucleus?
A. G1
B. S
C. G2
D. M
1.
2.
3.
4.
A
B
C
D
Chapter
Cellular Reproduction
Standardized Test
Practice
Which occurs in plant cells but not animal cells
during the cell cycle?
A. formation of a cell plate
B. formation of microtubules
C. formation of a cleavage furrow at the equator of
the cell
1.
A
2.
B
D. movement of chromosomes to the poles
of
the
3.
C
cell
4.
D
Chapter
Cellular Reproduction
Standardized Test
Practice
Multiple changes in DNA are required to
change an abnormal cell into a cancer cell.
A. true
B. false
1. A
2. B
Chapter
Cellular Reproduction
Standardized Test
Practice
Which is not a condition that can result in cancer?
A. a failure in the control mechanisms that regulate
the cell cycle
B. a failure in the repair systems that fix changes
or damage to DNA
C. a failure of the spindle fibers to move chromosomes
during mitosis
1.
A
D. mutations or changes in segments of DNA
that
2.
B
control protein production
3.
C
4.
D
Chapter
Cellular Reproduction
Glencoe Biology Transparencies
Chapter
Cellular Reproduction
Image Bank
Section 1
Cellular Reproduction
Vocabulary
Section 1
cell cycle
interphase
mitosis
cytokinesis
chromosome
chromatin
Section 2
Cellular Reproduction
Vocabulary
Section 2
prophase
sister chromatid
centromere
spindle apparatus
metaphase
anaphase
telophase
Section 3
Cellular Reproduction
Vocabulary
Section 3
cyclin
cyclin-dependent kinase
cancer
apoptosis
stem cell
Chapter
Cellular Reproduction
Animation
 Visualizing the Cell Cycle
Chapter
Cellular Reproduction