2. Cell division is necessary for normal growth, repair, and reproduction of an organism.
2 types of cells
somatic cells (body cells)
diploid cells - 2 sets of chromosomes (2n)
reproductive cells (sperm and egg)
haploid cells - single set of chromosomes (n)

3. Mitosis - process of cell division in which a somatic cell makes an identical copy of itself
involves one chromosome replication and 1 cell division
1 parent cell forms 2 identical daughter cells

4. Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

5. Longest part of the cell cycle
No division happens
G1 – growth of cell
S – (synthesis) DNA is copied

6. Each identical sister chromatid is joined at the centromere.

7. G2 – preparation to divide
Video Clip

8. The chromosomes condense into sister chromatids (visible)
Centrioles separate and move to opposite

9. Spindle fibers form between the centrioles
Nuclear membrane breaks apart
Video Clip

10. The chromosomes line up along the spindle fibers in the middle of the cell.
Video Clip

11. The sister chromatids separate at the centromeres
Chromatids are pulled to opposite ends of the cell by the spindle fibers.
Nuclear membrane forms again.
Video Clip

12. Spindle fibers dissolve
Nucleus reforms
Chromsomes unwind into chromatin.
Cell begins to “pinch in” (animal cell) or grow a cell plate (plant cell)
Cytokinesis – cytoplasm divides into 2 identical cells
Video Clip