Title: Mitosis
1Mitosis
- What is it?
- Why is it Important?
- What do I need to know?
2What is Mitosis?
- MITOSIS division of the nucleus into two
identical daughter cells
http//fairmanstudios.com/als.htm
3Why is mitosis important?
- Eukaryotes use cell division to create new cells
- Growth, Maintenance and Repair of body cells
- Asexual cell division
4What makes up the cell cycle?
5- Chromosome made of a DNA and protein complex
chromatinFollowing DNA replication, a chromosome
contains two sister chromatids attached by a
centromere -
MITOSIS is about organizing and distributing
Sister
Chromosome
Chromatids
CHROMOSOMES
Centromere
6What happens in INTERPHASE?
- Cells are in interphase 90 of the time
- G1 Gap 1 (cell growth)
- S chromosome synthesis (duplication)
- G2 Gap 2 (cell growth)
- M Mitosis
7INTERPHASE
nucleolus (if any) still visible
nuclear envelope clearly visible
chromatin, NO chromosomes, yet
8PROPHASE
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11PROPHASE
nuclear envelope disappears
nucleolus disappears
chromosomes become visible
12PROPHASE
Centrioles
Centrioles migrate form spindle.
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15Kinetochore (centromere)
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24plant cytokinesis
25Mitosis produces identical offspring (2N---2N)
26Why some cells stop mitosisdifferentiation
- Muscle cells
- Nerve cells
- Critical functions might be disrupted
- Adaptations to this condition
27Importance???
- Growth
- Replacement
- Cancer
- Regeneration of
28Cancer?
- Unregulated mitosis
- Benign
- Malignant/ metastasis
- How does it begin?
29Normal cycle controls
- Internal signals
- External signals
- growth factors
- fibronectin,etc
- carcinogens
- Apoptosis
- Immune functions
- And
30Cell immortilization!!
- Hayflick limit??
- Hela cells
- Contact inhibition
- Increased telomerase activity
- immortalization!
31Immortalization???
- If you replaced
- Why not??look at your shoestrings?
- Telomerase telomeres ?
- Recently
- Implications???
32Mitosis quiz
- Use two words to describe the importance of
mitosis - Draw and label the cell cycleinclude G1, S, G2,
M and cytokinesiswhat happens at each stage? - Why might telomerase be important?
- What disease is associated with mitosis?
- Are all organisms limited to 50 mitotic divisions?
33Name stage of mitosis
34Name stage of mitosis
35Name stage of mitosis
36Name stage of mitosis
37Name stage of mitosis
38Name stage of mitosis
39Name stage of mitosis
40Name stage of mitosis
41These are bacteria
- Watch the clip
- What kind of reproduction is shown here?
- What advantage does this confer on the organism?