1. Mitosis: The Mystery of Cell Division

2. Objectives When you complete this program you should be able to:
1. Define the term Mitosis.
2. List and describe the stages of mitosis.
3. Identify cells in various stages of
the cell cycle using a microscope.

3. Why is Mitosis Necessary?
The parent cell is too fat (too much volume) compared to its skin (surface area)
Wastes do not exit quickly
Nutrients do not enter quickly
Growth and development
Maintenance and repair

4. Cell Cycle Cell Cycle can be defined as the life span of the cell.
The cell cycle consists of…
Interphase
Mitosis
Cytokinesis
Remember
IPMAT!
Key Points to note here: Interphase and Mitosis are not the same thing.
Interphase is the normal process of cell growth and is only interrupted for the G2 phase, where chromosomes are replicated.
Also note that cytokinesis occurs post-mitosis and launches two new cells into interphase.

5. Interphase Organelles are multiplied
It madly copies its DNA in this phase in preparation for the inevitable cell division
Proteins necessary for metabolism multiply

6. Prophase Chromatin condenses to produce double-stranded chromosomes
                                                            
Chromatin condenses to produce double-stranded chromosomes
Centrioles (animal cell) or centrosomes (plant cell) go to opposing POLES or ends of the cell
Nuclear membrane begins to dissolve
Centrioles start casting out MITOTIC SPINDLE or NET

7. Metaphase – think “M” for MIddle
Chromosomes line up in the middle of the cell (equator/metaphase plate) attached to the spindle fibres at the centromere
Chromosomes are double-stranded here
Anaphase will not start until chromosomes are correctly lined up

8. ANAPHASE Chromatids are separated and move to the poles of cell
Spindle fibres hauled in by the centrioles
Equal distribution of DNA is the objective

9. Telophase Chromosomes reach the poles
Furrow appears between cells about to divide in animal cells - cell plate grows in the middle of plant cells to separate the two daughter cells
Cytoplasm and mitochondria are equally distributed to the daughter cells
Nucleus reappears
Chromosomes revert to chromatin

10. Interphase Plant Cell Animal Cell
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11. Prophase Plant Cell Animal Cell Spindle fibers Centrioles
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12. Metaphase Plant Cell Animal Cell
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13. Anaphase Plant Cell Animal Cell
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14. Telophase Plant Cell Animal Cell
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15. Animal Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

16. Plant Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

18. IPMAT – in the order of the letters (from bottom right to top left)

19. Onion Root Tips – a blazing area of Mitosis Activity

20. Summary The cell cycle is the life span of the cell.
Interphase is the first step in the cell cycle. Normal cell growth and DNA replication occur during interphase.
Prophase is the beginning of mitosis. The replicated chromosomes become visible in this phase. The nuclear membrane disappears
Metaphase follows prophase and is the stage in which the lining up of sister chromatids occurs at the metaphase plate.

21. Summary Cont.
Anaphase is the stage of mitosis in which the chromosomes begin moving to the poles of the cell.
Telophase marks the end of the mitotic process and the nucleus reappears
The two new daughter cells will now enter Interphase and begin the cell cycle over again.

22. Terms you must know! Chromatin Chromosome Chromatid Centromere DNA
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis G1 S G2
Centrosome
Centriole
Spindle fibres
Cleavage furrow
Cell plate
Daughter cell