1. How Cells Divide
Chapter 10

2. Cell Cycle “The sequence of growth and division in a cell”.
There are two periods in the cell cycle:
Interphase
Mitosis

3. Eukaryotic Cell Cycle Interphase G1 S G2 M (mitosis) C (cytokinesis)
Subdivided into 5 phases
C (cytokinesis)
Separation of 2 new cells
Interphase

5. Interphase

6. M phase Mitosis is divided into 5 phases: 1. Prophase 2. Prometaphase
4. Anaphase
5. Telophase

7. Prophase

8. Prometaphase

9. Metaphase

10. Anaphase

11. Telophase

12. C Y T O K I N E S s

13. Interphase
Prophase
Prometaphase
Metaphase
Anaphase
Telophase

14. Mitosis
Mitosis is responsible for the growth, development and repair of cells.
Growth factors –”chemicals that stimulate the division and differentiation of cells”.
Differentiation - when new cells take on special shapes or special functions
(muscle cells)

15. Control of the Cell Cycle
Current view integrates 2 concepts
Cell cycle has two irreversible points
Replication of genetic material
Separation of the sister chromatids
Cell cycle can be put on hold at specific points called checkpoints
Process is checked for accuracy and can be halted if there are errors
Allows cell to respond to internal and external signals

16. 3 Checkpoints G1/S checkpoint G2/M checkpoint
Late metaphase (spindle) checkpoint

17. Tumors
Occur when the cells lose control of the cell cycle, allowing the cells to grow uncontrollably.
Tumors -
can be benign
can be malignant

18. Cancer Cells that gain abnormal size, shape or abilities.
Ability to break free from the original tumor and invade healthy tissues, turning them into cancer cells.