1. Mitosis Review

2. The Cell Cycle (2 parts) G1 S G2 Mitosis telophase anaphase metaphase prophase interphase 1 2

3. Maintaining Chromosome Number chromosomes (unduplicated) in parent cell at interphase same chromosomes (duplicated) in interphase prior to mitosis mitosis, cytoplasmic division chromosome (unduplicated) in daughter cell at interphase chromosome (unduplicated) in daughter cell at interphase

4. Stages of Mitosis Prophase Metaphase Anaphase Telophase

5. Prophase New microtubules are assembled One centriole pair is moved toward opposite pole of spindle Chromatin condenses into chromosomes Nuclear envelope starts to break up

6. Transition to Metaphase Spindle forms Spindle microtubules become attached to the two sister chromatids of each chromosome

7. Metaphase All chromosomes are lined up at the spindle equator Chromosomes are maximally condensed

8. Anaphase Sister chromatids of each chromosome are pulled apart Once separated, each chromatid is a chromosome

9. Telophase Chromosomes decondense Two nuclear membranes form, one around each set of unduplicated chromosomes

10. Results of Mitosis Two daughter nuclei Each with same chromosome number as parent cell Chromosomes are in unduplicated form

11. Cytoplasmic Division Usually occurs between late anaphase and end of telophase Two mechanisms –Cell plate formation (plants) –Cleavage furrow (animals)

12. Animal Cell Division: Cleavage Furrow

13. Plant Cell Division: Cell Plate Formation cell wall former spindle equator cell plate vesicles converging

14. Let’s see real plant cells During Mitosis

15. Onion root tip mitosis - Interphase stage. Credit: © Carolina Biological/Visuals Unlimited

16. Onion root tip mitosis - Prophase stage. Credit: © Carolina Biological/Visuals Unlimited

17. Onion root tip mitosis - Metaphase stage. Credit: © Carolina Biological/Visuals Unlimited

18. Onion root tip mitosis - Early anaphase stage. Credit: © Carolina Biological/Visuals Unlimited

19. Onion root tip mitosis - Late anaphase stage. Credit: © Carolina Biological/Visuals Unlimited

20. Onion root tip mitosis - Telophase stage. Credit: © Carolina Biological/Visuals Unlimited

21. Onion root tip mitosis - Daughter cells. Credit: © Carolina Biological/Visuals Unlimited

22. Let’s try it together Click here to do the on-line lab