1. Cell growth and repair

2. Learning goals We are learning what is cancer.
We are learning the difference between the types of tumours.
We are learning the differences between a normal cell and cancer cell.

3. cell division frequency
growing organism = rapid mitosis of cells in areas of growth
cells likely to be damaged or injured as they function also have high rates of mitosis

4. Some examples
cell division happens at different rates depending on type of cell
nerve cells do not undergo mitosis once they mature
skin cells and cells in the digestive tract, undergo cell division regularly
Intestinal cells – roughly every three days
Red blood cells – roughly every four months

6. checkpoints
Proteins monitor cell activities and surroundings and send messages to nucleus G1
cell size, nutrients, growth factors, DNA damage G2
cell size, DNA replication M
chromosome attachments to spindles

7. checkpoints Cells remain in interphase if:
Signals from other cells not to divide
Not enough nutrients
DNA not replicated
DNA is damaged

8. G0 Phase Cells can enter a resting phase called G0
Temporary (muscle cells) or permanent (nerve cells, DNA damage)

9. Cell death Apoptosis Controlled death of old cells White blood cells
Necrosis
Cells may die due to external factors
Toxins, infections

10. cancer Abnormal cell division Mutations, carcinogens
Instead of apoptosis, these cells divide uncontrollably
Don’t stay in interphase

11. tumour Mass of cells continue to grow with no obvious function
Can reduce the effectiveness of surrounding tissue

12. tumours Benign – does not affect surrounding cells other than crowding
Malignant – interferes with surrounding cells; cancerous
Metastasis – cells that break away

14. cancer
May stimulate other cells to start replicating uncontrollably, thus spreading cancer and causing different types of cancer

15. causes Mutations – random changes in DNA
Carcinogens – environmental factor causing cancer
Mutagen – carcinogen that causes a mutation

16. A B C Ds A = asymmetry B = borders are irregular C = color
D = diameter

18. Let’s watch!
Video

20. Learning goals We are learning what is cancer.
We are learning the difference between the types of tumours.
We are learning the differences between a normal cell and cancer cell.