Mitosis Cell Division

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Mitosis (Cell Division)

• MITOSIS

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Vocab

• Cell Cycle the life cycle of a eukaryotic cell,
  consisting of chromosome duplication, mitosis,
  and cytokinesis
• Chromosomes coiled DNA and protein
• Binary fission when one bacteria cell splits
  into 2
• Homologous Chromosomes chromosomes with
  matching information

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Vocab cont.

• Chromatids identical chromosome copies, ½ of
  the X shape chromosome
• Centromere holds the chromatids together when a
  chromosome is duplicated

Centromere
Chromatid
Chromosome
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Vocab cont.

• Mitosis cell division
• Cytokinesis when the cytoplasm divides after
  mitosis
• Chromatin uncoiled DNA

Chromatin
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Limits to Cell Growth

• DNA Overload
• - DNA would not be able to instruct all of the
  activities going on in the cell
• Exchanging Materials
• - As the cell size increases it would be more
  difficult for a larger cell to get oxygen and
  nutrients in and wastes out

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Cell Division

• process by which a cell divides and produces 2
  identical daughter cells
• Why do cells divide?
• 1) Growth of the organism
• 2) Repair damaged cells
• 3) Reproduction

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The Steps of the Cell Cycle

• 4 phases
• G1 cell growth

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The Steps of the Cell Cycle

• 4 phases
• G1 cell growth
• S DNA
• replication

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The Steps of the Cell Cycle

• 4 phases
• G1 cell growth
• S DNA
• replication
• 3. G2 cell growth

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The Steps of the Cell Cycle

• 4 phases
• G1 cell growth
• S DNA
• replication
• 3. G2 cell growth
• 4. Mitosis
• - cell division
• (P, M, A, T)

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Interphase
Cell Membrane
Nucleolus

• - this is the longest
• phase of the cell
• cycle and includes the G1, S, and G2
  phases

Nuclear Membrane
chromatin(DNA)
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Mitosis

• Cell Division of body cells
• Shortest phase of the Cell Cycle
• Consists of 4 phases
• Prophase
• Metaphase
• Anaphase
• Telophase

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Mitosis Step 1 Prophase

• - DNA coils up into
• chromosomes, with 2
• copies of each chromosome
  (sister chromatids) held together by a
  centromere

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Mitosis Step 1 Prophase cont.

• - Nucleolus and Nuclear Mem.
  disappear
• - Spindle fibers form

Spindle Fibers
Chromosomes
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Mitosis Step 2 Metaphase

• - Chromosomes attach to spindle
  fibers by centromeres and line up
  across the middle

Spindle Fibers
One chromatid
Centromere
2nd chromatid
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Mitosis Step 3 Anaphase

• - Centromeres split apart
• - Sister chromatids are
  pulled to opposite ends of the cell by
  the spindle fibers

Spindle Fibers
One chromatid
2nd chromatid
Centromere
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Mitosis Step 4 Telophase

• - Chromosomes reach opposite
  ends of the cell
• - Nucleolus and nuclear
  membrane reappear

Nuclear Membrane
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Mitosis Step 4 Telophase cont.
Cleavage Furrow (Animal cell only)

• - Cell membrane begins to separate
• - Cytoplasm pinches in
• and divides evenly Cytokinesis
• - animal cells cleavage furrow
• - plant cells
• cell plate

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The Result

• 2 new identical daughter cells, the old cell no
  longer exists

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Animal Cell Mitosis
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Plants
Cell Plate