1. The Cell Cycle, Mitosis, and Cancer
Glencoe Biology Chapter

2. What causes cancer?
Cancer is caused by mutations which creates abnormal cell growth.
A mutation is a change to an organism’s DNA.

3. What causes mutations? (changes our DNA?)
Radiation
UV radiation
X rays
Chemicals
Alcohol
Tobacco
Drugs
Infectious agents
Viruses like HPV

4. Genetic Material
During most of the cell’s life, genetic material exists in chromatin
Chromatin = DNA that is long and tangled
Chromatin coils up (during M phase) to form chromosomes
When UNCOILED, chromatin makes proteins and can replicate itself
When COILED, cell division can occur

5. Anatomy of a Chromosome

6. The Cell Cycle The growth period is called INTERPHASE
The stage during which the cell carries out cellular functions
Also the stage in which it grows and replicates its DNA.
INTERPHASE S
(DNA synthesis) G1
Mitosis G2
Cytokinesis
MITOTIC
(M) PHASE

7. The Cell Cycle The nuclear division period is called M PHASE (Mitosis)G1 G2 S
(DNA synthesis)
INTERPHASE
Cytokinesis
MITOTIC
(M) PHASE
Mitosis
The nuclear division period is called M PHASE (Mitosis)
the stage of the cell cycle during which the cell’s nucleus and genetic material divide.
Consists of Prophase, Metaphase, Anaphase, and Telophase (PMAT)

8. The Cell Cycle The cytoplasmic division period is called CYTOKINESIS
The method by which a cell’s cytoplasm divides, creating a new cell.
INTERPHASE S
(DNA synthesis) G1
Mitosis G2
Cytokinesis
MITOTIC
(M) PHASE

9. Why do cells need to divide?
REPRODUCTION in UNICELLULAR organisms
Development, Growth, and Repair in SOMATIC (body) cells

10. INTERPHASE – BEFORE MITOSIS
centrioles
chromatin
Nuclear membrane

11. 1st stage of Mitosis: Prophase
During Prophase…
Chromatin coils up into visible chromosomes
The nucleus will disappear during this phase
Centrioles will begin to separate
centrioles
chromosomes
Nuclear membrane

12. 2nd Stage of Mitosis: Metaphase
During Metaphase…
Spindle fibers pull the chromosomes to the middle (equator/metaphase plate) of the cell

13. 3rd stage of Mitosis: Anaphase
During Anaphase…
Chromosomes will be pulled apart forming chromatids.
Once the chromatids are separated, they will move towards opposite sides of the cell.

14. 4th stage of Mitosis: Telophase
During Telophase…
The chromatids uncoil, becoming chromatin
The nuclear envelope reforms
Mitosis is COMPLETE!!!

15. Cytokinesis: last stage in the cell cycle
The cytoplasm divides into two new cells.
ANIMAL CELLS: The cell membrane will move inward and pinch apart
PLANT CELLS: A new cell wall (cell plate) forms between the two new cells.

16. SUMMARY - MITOSIS Number of ROUNDS of cell divisions: 1
Number of daughter cells :
Genetically identical? Yes
Chromosome #: Same as parent
Where: Somatic cells (non-sex cells)
When: Throughout life
Role: Growth and repair

17. The complete CELL CYLCLE cell cycle video
M-PHASE
(mitosis + cytokinesis)
MITOSIS

18. KARYOTYPE and Chromosome Number:
Human chromosome number:
46 in body (somatic) cells (diploid OR 2N)
23 in sex cells (egg and sperm) (haploid OR N)
A picture of species’ full set of chromosomes is a KARYOTYPE

19. S (DNA synthesis) INTERPHASEG1 G2 S
(DNA synthesis)
INTERPHASE
Cytokinesis
MITOTIC
(M) PHASE
Mitosis