How is the T7 bacteriophage regulated expression exploited in molecular biology?

If the lacZ protein breaks down lactose, is it worthwhile to make it when there is no lactose around? How does the bacteria use this system to efficiently control the production of the lacZ protein? Does the presence of lactose in the cell alter its ability to repress translation? To what does the lacI protein bind to? What effect does the lacI gene have on transcription of the lacZ and lacY genes?

A newly identified protein from the  cells of the Panopyra plant on Pandora was shown to inhibit translation of its target genes by binding to the 5’ UTR of the mRNA and preventing ribosome binding.  A possible way this inhibition may be relieved by an sRNA would be:  Group of answer choices a)The sRNA acts as a silencer, suppressing the inhibitory protein and allowing translation to take place. b)The sRNA acts as a decoy, sequestering the inhibitory protein and allowing translation to take place. c)The sRNA acts as a marker, flagging the inhibitory protein for ubiquitination and allowing translation to take place.

What role does an operator sequence serve in bacterial gene expression regulation? Describe one change in bacterial cells that can cause a repressor protein to go from inactive to active or from active to inactive.

RNA knockdown has become a powerful tool in the arsenal of methods used to repress gene expression. Briefly describe how gene expression can be knocked down. What effect would introducing siRNAs to TSC1 have on human cells?

What is an enhancer? What do these sequences contain bound to it? Do enhancers have to be near promoters?