1. KEY CONCEPT Cell cycle regulation is necessary for healthy growth.

2. I can identify and external factors that regulate cell division.
I can explain cancer in terms of the cell cycle.

3. Internal and external factors regulate cell division.
External factors include physical and chemical signals.
Growth factors are proteins that stimulate cell division.
Most mammal cells form a single layer in a culture dish and stop dividing once they touch other cells.

4. Two of the most important internal factors are kinases and cyclins.
External factors trigger internal factors, which affect the cell cycle.

5. Apoptosis is programmed cell death.
a normal feature of healthy organisms
caused by a cell’s production of self-destructive enzymes
occurs in development of infants
webbed fingers

6. Cell division is uncontrolled in cancer.
Cancer cells form disorganized clumps called tumors.
Benign tumors remain clustered and can be removed.
Malignant tumors metastasize, or break away, and can form more tumors.
cancer cell
bloodstream
normal cell

7. Cancer cells do not carry out necessary functions.
Cancer cells come from normal cells with damage to genes involved in cell-cycle regulation.

8. Carcinogens are substances known to promote cancer.
Standard cancer treatments typically kill both cancerous and healthy cells.

9. Proteins that bind to cells and stimulate cell division are called
a. enzymes.
b. kinases.
c. growth factors.
d. carcinogens.

10. What is the term for the programmed death of cells?
a. kinase
b. cyclin
c. carcinogen
d. apoptosis

11. Two internal factors that are important in advancing the cell cycle are
a. kinases and cyclins.
b. hormones and enzymes.
c. phosphates and enzymes.
d. proteins and platelets.

12. Which phrase best describes cancer?
a. absence of cyclins
b. multiple gene mutations
c. uncontrolled cell growth
d. presence of genetic defects

13. Substances known to produce or promote cancer are called
a. carcinogens.
b. kinases.
c. cyclins.
d. malignancies.