1. Regulation Contact Inhibition Signals cells to stop dividing
Proteins on cells
Proteins from other organs
Environmental conditions (availability of nutrients)

2. Checkpoints
Feedback signals at key checkpoints delay or stop next phase of cycle
G1 (Cells not healthy, too small, or conditions unsuitable for division)
G2 (Recognize mistakes in DNA, or cell still too small)
M [Metaphase] (Chromosomes not properly aligned to spindle fibers)

4. Cancer Uncontrolled cell division (Responds improperly or not at all)
Form tumors – mass of cells
Benign (Localized)
Malignant (Metastasis)

5. Cancer
Treatment-
Surgery
Chemotherapy
Radiation

6. Cancer Prevention Avoidance UV radiation – cause skin cancer
Chemicals- nicotine causes lung, trachea, mouth cancer

7. Assessment Checkpoints in cell cycle: A. signal cell death.
B. maintain the homeostatic environment of cells interior.
C. check that cell division occurs when cell is of suitable size and has met necessary internal conditions.
D. limit the occurrence of cancer cell development to only 1% of cell reproduction events.