1. Mitosis Ch 8. 2 Cell Division

2. Cell Cycle Interphase: Interphase: –G1: Cell grows –S: DNA replicates –G2: Organelles replicate

3. Mitosis The process of dividing nuclear material The process of dividing nuclear material

5. Vocab WRITE THESE DEFINITIONS ON TOP OF YOUR NOTES! Microtubules: protein structures that are part of a cell’s cytoskeleton Microtubules: protein structures that are part of a cell’s cytoskeleton –Spindle: a bundle of microtubules that separate chromosomes during mitosis –Centriole: microtubule structure that helps organize the spindle fibers during cell division –Aster: microtubules surrounding the centriole

6. Prophase a. Chromosomes become visible. b. Centrioles move to opposite poles of the cell. c. Microtubules extend from the centrioles to form asters

7. Prophase d. Microtubules form spindle fibers. e. Spindle fibers become attached to centromeres. f. Nuclear membrane disappears.

9. Metaphase a. Centromeres of the chromosomes line up on the equator.

10. Anaphase a. Centromeres divide. b. Chromatids move to opposite poles.

11. Telophase a. Chromosomes reach the poles of the cell. b. Chromosomes uncoil. c. Spindle and asters disappear. d. Nuclear membrane forms.

13. Cytokinesis (in animals) a. Begins during late anaphase. b. Cytoplasm is pinched off by cell membrane. c. Results in two new cells.

14. Mitosis in plants Main events are the same Main events are the same Plants don’t have centrioles or asters. Plants don’t have centrioles or asters. In cytokinesis, a cell plate forms between the new cells. In cytokinesis, a cell plate forms between the new cells.

15. The Rate of Mitosis WRITE THESE DOWN! Cells undergo mitosis at different rates. Cells undergo mitosis at different rates. Mitosis speeds up during an injury. Mitosis speeds up during an injury. Mitosis slows down with aging. Mitosis slows down with aging. Cells that undergo very fast uncontrolled mitosis form cancer. Cells that undergo very fast uncontrolled mitosis form cancer.

16. Name the stage of each cell. A B D C