Essentials of Genetics 9th Edition by Michael Palladino William Klug, Michael Cummings, Charlotte Spencer

Exercise 1

In this chapter, we have focused on how prokaryotic and eukaryotic organisms regulate the expression of genetic information. In particular, we discussed both transcriptional and posttranscriptional gene regulation. Based on your knowledge of these topics, answer several fundamental questions:
(a) How do we know that bacteria regulate the expression of certain genes in response to the environment?
(b) How do we know that bacterial gene clusters are often coordinately regulated by a regulatory region that must be located adjacent to the cluster?
(c) What led researchers to conclude that a trans -acting repressor molecule regulates the lac operon?
(d) How do we know that promoters and enhancers regulate transcription of eukaryotic genes?
(e) How do we know that DNA methylation plays a role in the regulation of eukaryotic gene expression?