1. Mitosis Cell Reproduction

2. Mitosis Definition: Cell Division that produces two cells that are identical to each other and to the parent cell. Definition: Cell Division that produces two cells that are identical to each other and to the parent cell. This produces body cells so the organism can grow or replace dead/damaged cells. This produces body cells so the organism can grow or replace dead/damaged cells.

3. “C” Words: Chromatin-Strands of DNA in a cell that is not dividing— unwound and indistinct. Chromatin-Strands of DNA in a cell that is not dividing— unwound and indistinct. Chromosomes- Strands of DNA in a cell that is dividing— wound up and distinct. Chromosomes- Strands of DNA in a cell that is dividing— wound up and distinct. Chromatin is unwound and indistinct in the nucleus of the cell.

4. More “C” Words: Chromatids—one of 2 identical strands of DNA in a chromosome (called sister chromatids) Chromatids—one of 2 identical strands of DNA in a chromosome (called sister chromatids) Centromere—the structure that holds together the 2 sister chromatids. Centromere—the structure that holds together the 2 sister chromatids. Histones-protein “beads” that keep the strand of DNA from tangling up.

5. Chromosome Structure When cells begin to divide, the first thing that happens is that the chromatin in the nucleus begins to wind up, separating the strands from each other. When cells begin to divide, the first thing that happens is that the chromatin in the nucleus begins to wind up, separating the strands from each other. Each chromosome consists of 2 identical strands of DNA (called sister chromatids) held together with a centromere.

6. More “C” Words Centrosome/Centriole -Structure found in animal cells that anchors the spindle fibers Centrosome/Centriole -Structure found in animal cells that anchors the spindle fibers Cytokinesis—the division of the cytoplasm following mitosis (the dividing of the nucleus) Cytokinesis—the division of the cytoplasm following mitosis (the dividing of the nucleus)

7. Cell Cycle

8. Interphase Interphase A cell in Interphase is not actively dividing. It is working very hard, however—growth, replicating DNA and preparing to divide. DNA is in the form of chromatin here:

9. Prophase Centrioles migrate to the poles. Nuclear Membrane disappears. Chromatin winds up to form chromosomes. Spindle forms. Prophase

10. Metaphase Metaphase Chromosomes move to the equator of the cell.

11. Anaphase Chromosomes split in half at centromere. Each chromatid moves to opposite poles.

12. Chromosome Structure At Anaphase Centromere splits and chromatids go to opposite poles of cell Chromosomes prior to Anaphase ^

13. Telophase Telophase Chromosomes unwind to form chromatin again. New nuclear membranes form. Spindle disappears

14. Cytokinesis Cytokinesis in an Animal Cell: A cleavage furrow forms, eventually pinching in the cell membrane to form 2 cells. Cytokinesis in a Plant Cell: A cell plate forms between the 2 new nuclei— eventually dividing the cell into 2 cells. The cell plate becomes the new cell wall.

15. Cytokinesis in Animal Cells (on left) and Plant Cells (on right)

16. Summary of Mitosis

17. Mitosis Animation http://www.cellsalive.com/mitosis.htm http://www.cellsalive.com/mitosis.htm http://www.cellsalive.com/mitosis.htm http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__mitosis_and_cytokin esis.html http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__mitosis_and_cytokin esis.html http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__mitosis_and_cytokin esis.html http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ chapter2/animation__mitosis_and_cytokin esis.html http://www.youtube.com/watch?v=VlN7K 1-9QB0 http://www.youtube.com/watch?v=VlN7K 1-9QB0 http://www.youtube.com/watch?v=VlN7K 1-9QB0 http://www.youtube.com/watch?v=VlN7K 1-9QB0