1. Cell Growth and Division
The Cell Cycle & Mitosis

2. ¿ Are cells always dividing?
Sometimes they are growing
Sometimes they are preparing to divide
Sometimes they are dividing

3. Cell Division = Mitosis
During life, we go from one cell to ~ 75 trillion cells.
Mitosis = division of body cells
Cancer = uncontrolled cell division

4. Cells that rarely divide
Mature skeletal muscle cells
Nerve cells

5. Cells that constantly divide
Skin cells
Cells that line gastro-intestinal tract

6. Cell cycle
= Period of time between
one cell division & the next

7. Cell cycle – Phases
I. Interphase
G1 - rapid cell
growth
- basic
cell f(x)s

8. I. Interphase S = Synthesis – DNA replication G2 = Organelles &
cytosol made G1 S G2

9. Cell cycle - Phases
II. Mitosis = cell division
III. Cytokinesis = cytoplasm division
?s 1-7

10. Sequence of Cell Cycle
Interphase
Prophase
Metaphase
Anaphase
Telophase

11. (division of cytoplasm)
Mitosis Includes :
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
(division of cytoplasm)

12. Cell during Interphase :
DNA in form of chromatin
Looks like
hair / spaghetti
(chrs. *
not visible)
* chromosomes

13. Prophase Chrs. coil and become visible
Sister chromatids move towards poles
Spindle forms
Nuclear envelope & nucleoli disappear

14. Metaphase Sister chromatids line up at equator on metaphase plate
(Meet me
in the middle)

15. Anaphase Centromeres divide, chromatids split
Sister chromatids move to opposite poles (centrioles)
(Run away, run away!)

16. Telophase Chrs. uncoil and become invisible (now in form of chromatin)
Spindle disappears
Nuclear envelope & nucleoli re-appear

17. Cytokinesis Division into two identical DAUGHTER CELLS
Starts during Telophase
Finishes after Telophase is over
animation

18. Whitefish cells during mitosis