1. Mitosis Biology I G/T

2. Why do cells divide? To make a new organismTo make a new organism GrowthGrowth RepairRepair Replacement of normal cell lossReplacement of normal cell loss DevelopmentDevelopment

3. Structure of the Mitotic Chromosome Showing Sister Chromatids, Centromeres, and Spindle Fiber Attachment Chromatid – ½ of a chromosome Chromatid – ½ of a chromosome Sister chromatid – each half of the same chromosome – they are identical Sister chromatid – each half of the same chromosome – they are identical Centromere – complex of proteins attached to DNA holding the sister chromatids together Centromere – complex of proteins attached to DNA holding the sister chromatids together

4. Stages of Mitosis Interphase S Stage

5. Interphase Interphase is not part of mitosis – it is the time between cell divisions Interphase is not part of mitosis – it is the time between cell divisions Interphase includes G1, S, and G2 Interphase includes G1, S, and G2 During interphase the cell is doing its normal metabolic activities like protein synthesis During interphase the cell is doing its normal metabolic activities like protein synthesis The cells are performing their duty as part of a tissue The cells are performing their duty as part of a tissue The DNA duplicates to get ready for mitosis The DNA duplicates to get ready for mitosis The DNA is in chromatin form The DNA is in chromatin form Animal Cell Plant Cell

6. Prophase

7. Prophase   The chromatin begins to condense into chromosomes and become visible in the nucleus   The nuclear membrane begins to break down   Centrosomes duplicate, form spindles, & move to the poles   Spindle fibers attach to the chromosomes begin moving Animal Cell Plant Cell

8. Metaphase

9. Metaphase The chromosomes are lined up down the equator by the spindles The chromosomes are lined up down the equator by the spindles Animal Cell Plant Cell

10. Anaphase

11. Anaphase The sister chromatids separate at the centromeres The sister chromatids separate at the centromeres Each chromatid (now called a chromosome) heads to the pole of the cell Each chromatid (now called a chromosome) heads to the pole of the cell Animal Cell Plant Cell

12. Telophase http://www.bioweb.uncc.edu/biol1110/Stages.htm

13. Telophase Animal Cell Plant Cell

14. Interphase After telophase is complete, the cells reenter interphase and go about their normal business After telophase is complete, the cells reenter interphase and go about their normal business The DNA is totally decondensed, new nuclei reformed, and there are totally 2 new cells The DNA is totally decondensed, new nuclei reformed, and there are totally 2 new cells

15. Differences Plant vs. Animal Cell Mitosis Plant cells do not have centrioles in their centrosomes but animal cells do ????? Plant cells do not have centrioles in their centrosomes but animal cells do ????? Plant cells cannot pinch in due to the cell wall – a new cell wall forms down the middle from the endoplasmic reticulum Plant cells cannot pinch in due to the cell wall – a new cell wall forms down the middle from the endoplasmic reticulum Plant cells divide slower due to having to reform the cell wall Plant cells divide slower due to having to reform the cell wall Cytokinesis in an animal cell Cytokinesis in a plant cell plant mitosis plant mitosis plant mitosis plant mitosis fluorescent animal cell mitosis fluorescent animal cell mitosis fluorescent animal cell mitosis fluorescent animal cell mitosis animal cell mitosis animal cell mitosis animal cell mitosis animal cell mitosis

16. Mitosis Quiz – Animal Cells Metaphase Interphase Interphase Anaphase Telophase Prophase

17. Mitosis Quiz – Plant Cells http://biology.nebrwesleyan.edu/benham/mitosis/ Metaphase Telophase Anaphase Interphase Prophase Interphase