Question 20 (1 point) Which of the following is TRUE of carcinogenesis? a) abnormal activation of genes that promote apoptosis may contribute to carcinogenesis b) most neoplasms demonstrate a single central mutation that triggered neoplastic transformation c) the latent period between exposure to a carcinogen and the development of a tumor may span decades Question 21 ( 1 point) Which of the following statements regarding the role of oncogenes in carcinogenesis is TRUE? a) regulate apoptosis of cells with DNA damage b) oncogenes code for oncoproteins which promote cell growth c) the viral DNA of oncogenic DNA viruses behaves as a proto-oncogene.