For normal cells, the rate of cell division is carefully regulated so just enough cells are produced to replace
damaged cells and to provide cells needed for normal growth. Cancer begins when some cells escape from the
normal controls on cell division, so too many cells are produced. To learn more about how cancers develop,
read "Understanding Cancer", available at https://www.cancer.gov/about-cancer/understanding/what-is-cancer
or the associated student handout available on Canvas (recommended).
1. In situ or benign tumors can usually be treated successfully by surgical removal. In contrast,
cancers (i.e., tumors which have become malignant) are much more dangerous and harder to
treat. Explain why. (5 pts)
Fig: 1