What is the Ames test and how is it carried out? What assumption concerning mutagenicity and carcinogenicity is it based upon?

Should the exposome field focus exclusively on measuring chemicals derived from exogebeous sources or should the field also evaluate the chemicals generated and processed from endogeneous sources?   If a study of the human genome gave rise to genomics, does the human exposome give rise to a new field of exposomics?

During an Ames test, bacteria were exposed to a potential mutagen.Also, as a control, another sample of bacteria was not exposedto the mutagen. In both cases, 10 million bacteria were plated andthe following results were obtained:No mutagen:               17 coloniesWith mutagen:         2017 coloniesCalculate the mutation rate in the presence and absence of the mutagen.How much does the mutagen increase the rate of mutation?

Dr. Serena Velazquez lands a coveted post-doc position at Johns Hopkins following completion of her MD/PhD in cancer therapeutics to treat late-stage pancreatic cancer using a mouse model. Her post-doc will be devoted to targeted mutagenesis of replicative enzymes to halt cell division in cancerous cells. She reviews mitosis and meiosis before reporting for her first day of work.   1)  Dr. Velazquez considers targeted mutagenesis of DNA ligase. What would that do?   a)  Prevent dsDNA from binding to SSB. b) Prevent the leading strand from being able to unite together Okazaki fragments. c) Prevent the lagging strand from being able to unite together Okazaki fragments. d)Prevent replication of DNA.