1. Pö ÿalima 02-26-10  Cell Division  You will need your computer today

2. 10.2 Goals  I will be able to explain what happens in the cell cycle.  I will be able to explain and identify the stages of mitosis.

3. Mitosis 10.2

4. Cell cycle = Life span of the cell  G 1 phase – cell grows, makes more organelles and proteins  S phase – chromosome replication (S = synthesis = “to make”) S phase G1 phase G2 phase

5. Chromosomes and Chromatid  Each chromosome made of two identical chromatids.  Attached together by the centromere

6. Cell cycle = Life span of the cell  G 1 phase – cell grows, makes more organelles and proteins  S phase – chromosome replication (S = synthesis = “to make”)  G 2 phase – molecules and organelles required for cell division produced  M phase – mitosis and cytokinesis  Interphase – G 1, S, G 2 S phase G1 phase G2 phase

7. CELL DIVISION  Eukaryotes (cells with a nucleus) go through 2 stages of division  Mitosis – division of the nucleus  Cytokinesis – division of the cytoplasm

8. MITOSIS  4 phases of nuclear division

9. Prophase  Longest phase of mitosis  Chromosomes become visible  Centriole pairs begin to separate  Spindle fiber forms (made of microtubules)  Nuclear envelope breaks down  Spindle begins to attach to chromosomes at the centromere

10. Metaphase  Chromosomes line up across center of the cell (“equator” or “metaphase plate”)  Centriole pairs at opposite ends of the cell  Centromere connected to the spindle fibers

11. Anaphase  Sister chromatid split apart  Chromosomes get pulled to opposite poles by the shrinking spindle fibers

12. Telophase  Chromosomes decondense  Nuclear envelope reforms around each set of chromosomes at opposite ends of the cell  2 nuclei are formed

13. Cytokinesis  Division of the cytoplasm  2 new daughter cells are formed with the same number of chromosomes as the original cell.

14. Video of Mitosis  http://highered.mcgraw- hill.com/sites/0072437316/student_view0/chapter11/anim ations.html# http://highered.mcgraw- hill.com/sites/0072437316/student_view0/chapter11/anim ations.html#  http://www.youtube.com/watch?v=s1ylUTbXyWU&featur e=related http://www.youtube.com/watch?v=s1ylUTbXyWU&featur e=related

15. Name the stages…

16. Try This Virtual Lab  http://bio.rutgers.edu/~gb101/lab2_mitosis/section1_fram es.html http://bio.rutgers.edu/~gb101/lab2_mitosis/section1_fram es.html

17. Homework  Online Mitosis W/S  Mitosis Flipbook. Include:  Interphase, pro-, meta-, ana-, telo-, cytokinesis

18. Homework  Pg. 249 #1-6  Pg. 257 #13-14