Question

Which of the following best accounts for the difference in mutagenic activity between PAHs and PAHs plus liver preparation?

a. in the absence of liver preparation, the bacteria metabolized the polynuclear aromatic hydrocarbons into mutagenic agents
b. in the presence of the liver preparation, histidine could not be synthesized by the bacteria
c. the enzymes in the liver preparation resulted in the metabolic activation of the polynuclear aromatic hydrocarbons into a carcinogenic chemical
d. the exposure of the bacteria to human cellular components resulted in the back-mutation of the polynuclear aromatic hydrocarbons

Answer 1

Answer: C

Step-by-step explanation:

Some poly nuclear aromatic hydrocarbons are not carcinogenic in themselves. However, when these are made to interact with living cells, enzymes in the cells could convert the polynuclear aromatic hydrocarbon into a carcinogenic material such as benzo-[a]-pyrene. This can now interact adversely with the deoxyribonucleic acid of living cells leading to genetic mutation, that is, irreversible changes in the genes of organisms.