1.What types of evidence indicate that cancer arises from genetic changes?

2.How can it be true that many types of cancer are genetic and yet not inherited?

3.Outline Knudson’s two-hit hypothesis of retinoblastoma and describe how it helps to explain unilateral and bilateral cases of retinoblastoma.

4.Briefly explain how cancer arises through clonal evolution.

5.What is the difference between an oncogene and a tumor-suppressor gene? Give some examples of the functions of proto-oncogenes and tumor-suppressor genes in normal cells.

6.How do cyclins and CDKs differ? How do they interact in controlling the cell cycle?

7.Briefly outline the events that control the progression of cells through the G₁/S checkpoint in the cell cycle.

8.Why do mutations in genes that encode DNA-repair enzymes often produce a predisposition to cancer?

9.What role do telomeres and telomerase play in cancer progression?

10.Briefly outline some of the genetic changes that are commonly associated with the progression of colorectal cancer.

11.Explain how chromosome deletions, inversions, and translocations can cause cancer.

12.Briefly outline how the Philadelphia chromosome leads to chronic myelogenous leukemia.

13.What is genomic instability? Give some ways in which genomic instability can arise.

14.How do viruses contribute to cancer?