1. Cell Division Mitosis and Meiosis

2. DNA deoxyribonucleic acid
DNA contains the genetic instructions for our cells. deoxyribonucleic acid

3. Chromosomes Chromosomes are made of strands of DNA
Most human cells have 46 chromosomes.
A cell with all of the chromosomes present is called diploid

4. Chromatin
Chromatin is chromosomes paired with proteins

5. Cell division in prokaryotes

6. Cell division in eukaryotes- The Cell Cycle

7. G1 Phase: Cell growth This is when cells grow Increase in size
Make new proteins and organelles

8. S-phase- DNA replication
DNA is synthesized when chromosomes are copied

9. G2-phase: preparing for cell division
Organelles are made
Molecules are produced

10. M phase: Cell Division
Mitosis – this is when the cell actually divides!
Steps in Mitosis:
Prophase – Metaphase – Anaphase - Telophase

11. prophase The chromosomes condense and become visible
The centrioles form and move toward opposite ends of the cell ("the poles")
The nuclear membrane dissolves
The mitotic spindle forms 

12. metaphase The Centrioles complete their migration to the poles
The chromosomes line up in the middle of the cell ("the equator")

13. Anaphase
Mitotic spindles begin to shorten, pulling chromatids apart

14. telophase
The chromosomes decondense
The nuclear envelope forms

15. Cytokinesis Cell membrane pinches in to form two cells
These cells are now in interphase

17. Regulating Cell growth
What controls cell growth?
Cells in contact with each other usually stop dividing, however many other factors are at work including:
Cyclin - a protein that signals a cell to begin reproducing
Internal & External regulators

18. Internal regulators
Proteins in the cell that regulate mitosis, making sure that each phase is completed before the next phase begins

19. External regulators
Proteins that respond to events to outside of the cell
Growth – signal to a cell to begin mitosis when certain events occur like:
Cuts, breaks, scratches

20. Apoptosis – programmed cell death
Some cells contain instructions in the DNA that control when the cell will die
Chromatin shrinks, the cell membrane breaks apart and then the cell is digested by other cells

22. Cancer
What is cancer?
Unregulated cell growth caused by cells losing control of cellular division
Uncontrolled cell division

23. Tumors A mass of cells that have divided uncontrolled
Benign tumors: non-cancerous, meaning that they will not spread (localized)
Malignant tumors: cancerous, meaning that the cells may, have or will spread

24. What causes cancer?
Defects in the genes that regulate and control cell division
Can be caused by:
Environmental Factors
Genetic Factors

25. Cancer treatments Not all cancer types are treatable
Advanced stages of cancer are often too far gone to treat
Treatments include
Surgery
Radiation
Chemotherapy
Stem Cells