The Cell Cycle SB2e E? What are the advantages and disadvantages of sexual and asexual reproduction?

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The Cell Cycle SB2e E? What are
the advantages and disadvantages of sexual
and asexual reproduction?

• Why does a cell divide?

• New cells replace dead cells
• Cells cant be too big because
• materials can not be transported fast enough
• Proteins can not be produced fast enough
• Volume increases faster than surface area
• O2, waste and nutrients can not diffuse fast
  enough

• For growth
• For development
• For repair
• For asexual reproduction
• For gamete production
• Sperm or eggs

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  The Cell Cycle
Section 10-2
M phase
G1 phase
S phase
G2 phase
Go to Section
3
Interphase

• Nucleus clearly seen
• Period of growth and repair G1
• DNA is in the form of chromatin
• DNA is replicated S phase
• Centrioles duplicate
• In plant cells asters duplicate

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Interphase
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
Go to Section
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Mitosis The Division on Nuclear
Material

• Prophase
• Metaphase
• Anaphase
• Telophase

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Prophase-1st stage of Mitosis Prometaphase

• Chromatin coils to form visible chromosomes
• Nuclear membrane and nucleolus begin to disappear
  
• Spindle fibers form between centrioles
• PrometaphaseChromatids attach to spindle fibers
  at centromeres

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Prophase
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
Go to Section
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Metaphase

• Chromosomes move to equator
• Centrioles reach opposite poles

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Metaphase
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
Go to Section
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Anaphase

• Centromeres split due to replication
• Sister chromatids separate
• Chromosomes move towards poles

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Anaphase
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
Go to Section
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Telophase

• Chromosomes reach opposite poles
• Nucleolus and nuclear membrane begin to reappear
• Chromosomes begin to uncoil into chromatin
• Cleavage-pinching in of cell membrane

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Telophase
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
Go to Section
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Cytokinesis
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
Go to Section
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Division of Cytoplasm Cytokinesis

• Animals
• Cytoplasm pinches near equator
• Two new cells form

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Cell plateforming

• Plants
• Plasma membrane does not pinch
• Cell plate forms across equator

• Animals
• Cytoplasm pinches near equator
• Two new cells form

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INTERPHASE
PROPHASE
Centrosomes(with centriole pairs)
Early mitoticspindle
Centrosome
Fragmentsof nuclearenvelope
Kinetochore
Chromatin
Centrosome
Spindlemicrotubules
Nucleolus
Nuclearenvelope
Plasmamembrane
Chromosome,consisting of twosister chromatids
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METAPHASE
TELOPHASE AND CYTOKINESIS
ANAPHASE
Cleavagefurrow
Nucleolusforming
Metaphaseplate
Nuclearenvelopeforming
Spindle
Daughterchromosomes
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Results

• Guarantees genetic continuity
• Two new cells with chromosomes identical to
  parent cell are formed

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1. The stage when Chromosomes become
visible________________

• 2. The stage of growth Repair,_________
• 3. The stage when the chromosomes are moving
  to opposite ends.__________
• 4. The stage where the centromeres split
  ________________
• 5. DNA is copied_________________
• 6. 2 new daughter nuclear membranes begin to
  appear__________________
• 7. Each chromatid becomes a separate
  chromosome________________

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True/False

• 8. Cell size is important in the cell cycle?
• 9. The nucleolus is present in Interphase,
  Prophase, Telephase, Cytokenesis?
• 10. Chromosomes become attached to spindle
  fibers during prophase?
• 11. Write the order of the stages in the cell
  cycle.

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Answers

• 1. Prophase
• 2. Interphase
• 3. Anaphase
• 4. anaphase
• 5. Interphase
• 6. Telephase
• 7. anaphase
• 8. T 9. T 10. T
• 11. I/PMAT/C

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Cancer

• Uncontrolled growth of cells
• Mutation in the gene that regulates growth and
  division
• Lifestyles risks/Carcinogen
• Tobacco
• UV radiation
• Alcohol
• Diet
• Chemotherapy and radiation

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• Petri dish showing normal division of cells.
• 3rd dish shows cells separated in middle of dish.
• 4th 5th dish show how the cells will grow and
  divide to fill up the whole dish and stop.
• If the 5th dish held cancer cells then they would
  not stop but continue to grow over the edges/rim
  of the petri dish.