1. MITOSIS AN ANIMATION OF CELL DIVISION BY: MRS. MILLER

2. What do you think? 1. Watch Video. 2. Watch Video and make observations (drawings and words). 3. Watch Video to see if you missed anything. Mitosis – The process of cell division, in which a cell is copied exactly. (it has the same number of chromosomes as the original cell) WHAT IS MITOSIS

3. SUPPORTING VOCABULARY Cell cycle - The life cycle of a cell that begins when the cell is formed and ends when the cell divides and forms new cells. DNA – Genetic material that carries information to make new cells. Chromosomes – Structures that DNA is organized into. Centromere – A region within a cell in which chromatids are held together.

4. Animal Cell Reproduction (Mitosis) Plant Cell Reproduction (Mitosis)

5. REASONS FOR MITOSIS Cells need to divide and duplicate for the following reasons: 1. Growth – young organisms grow into adults throughout their life cycle 2. Repair – new cells are needed to repair damage (ie. cuts, broken bones) 3. Replacement – new cells need to replace old cells (ie. skin cells, lining of stomach and small intestine)

6. HOW DOES IT WORK? Preparing to divide = Interphase Mitosis Phases: 1. Prophase 2. Metaphase 3. Anaphase 4. Telophase After division = Cytokinesis

7. INTERPHASE: COPYING DNA Cell Nucleus Nucleolus Chromosomes Centrioles (animal cells only)

8. COPYING DNA: INTERPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Chromosomes are copied.

9. COPYING DNA: INTERPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Centrioles move to opposite poles (sides) of the nucleus.

10. MITOSIS PHASE 1: PROPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Nuclear membranes dissolve.

11. MITOSIS PHASE 1: PROPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Chromosomes condense into rodlike structures.

12. MITOSIS PHASE 2: METAPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Nucleolus spreads out into string-like fibers.

13. MITOSIS PHASE 2: METAPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Chromosomes line up along the equator.

14. MITOSIS PHASE 3: ANAPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Chromatids separate and move to opposite sides of the cell.

15. MITOSIS PHASE 4: TELOPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Chromatids separate even farther.

16. MITOSIS PHASE 4: TELOPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Nuclear membranes form around each set of chromosomes.

17. MITOSIS PHASE 4: TELOPHASE Cell Nucleus Nucleolus Chromosomes Centrioles Chromosomes unwind.

18. CYTOKINESIS: THE CELLS DIVIDE Cell Nucleus Nucleolus Chromosomes Centrioles Cytoplasm divides and is pinched off from the membrane.

19. ASSIGNMENT Fold 6 pieces of white paper almost in half (leave room to title each at the bottom). Glue the longer side of each piece to construction paper. Write the phase on the longer portion. Draw a picture of the phase on the front. On the inside explain what happens in each phase. Write to inform on the additional paper provided. This must be at least one paragraph that includes why mitosis happens and describe a cell cycle.