(a)[3]
Explain how uncontrolled cell division can lead to cancer.
(b)[3]
Describe the experimental evidence that indicates smoking causes lung cancer.
(c)[3]
Fig. 6.1 shows how mortality rates for lung cancer in five countries changed between 1950 and 2006 for males. Using Fig. 6.1, describe both the similarities and the differences in the mortality-rate trends for the countries shown.