Transcript Cellular Reproduction
Cellular Reproduction
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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 Click on a lesson name to select.
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, G 1 *Immediately after a cell divides.
(Gap 1) 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, G 2 (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.
D.
cells with lower surface area to volume ratio 1.
A cells shaped like a cube 2.
B 3.
4.
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.
C.
divide.
D.
The cell’s cytoplasm divides.
2.
3.
4.
A B C D
Section 2 Cellular Reproduction Mitosis and Cytokinesis
The Stages of Mitosis
Prophase The cell’s chromatin tightens.
Sister chromatids centromere .
are attached at the 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.
B.
C.
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 D.
ultraviolet radiation from the Sun 1.
2.
3.
4.
A B C 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
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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 D.
2.
3.
4.
A B C D
Chapter Cellular Reproduction Standardized Test Practice
Which cell has the lowest ratio of surface area to volume?
C B A
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.
G 1 B.
S C.
G 2 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.
D.
formation of a cleavage furrow at the equator of the cell 1.
A movement of chromosomes to the poles of the cell 2.
3.
4.
B C 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.
B.
C.
D.
a failure in the control mechanisms that regulate the cell cycle a failure in the repair systems that fix changes or damage to DNA a failure of the spindle fibers to move chromosomes during mitosis mutations or changes in segments of DNA that control protein production 1.
2.
3.
A B 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
Chapter Cellular Reproduction