2.  All living things are made of cells.  Cells are the basic unit of life.  Cells come from other cells. Schwann – animal cells 1839 Schleiden – plant cells 1839 Virchow – cell come from pre-existing cells 1855

5.  This process of division is called Mitosis. It occurs in multiple stages or phases. You will learn the details of this process in high school biology.  However, today, we are observing cells that are going through different stages of the reproductive process called Mitosis.

6. Onion Root Cell Reproduction

7. Steps of Mitosis

8. INTERPHASE PROPHASE METAPHASE ANAPHASE TELOPHASE CYTOKINESIS Normal Cell Activities – DNA in chromosomes is copied at end of stage Chromosomes line up in middle of cell (in pairs – sister chromatids) Nuclear membrane forms around both ends of chromatids. Cell membrane separates into two new cells. Chromosomes thicken and become visible. (getting ready to divide) Chromatids pull apart – half go to each side

9. http://www.biologycorner.com/projects/mitosis/whit efish_embryo.html http://www.biologycorner.com/projects/mitosis/o nion_root.htm l Whitefish Mitosis Onion Root Tip Mitosis

10. Where would you say cells come from? How do cells reproduce?

11. Where would you say cells come from? Cells come from other cells. How do cells reproduce?

12. Where would you say cells come from? Cells come from other cells. How do cells reproduce? Cells divide through MITOSIS.