Are humans an example of a placental mammal? Justify

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

How are proteins and nucleic acids related? they both provide energy. they both carry genetic information. the structure of proteins is determined by nucleic acids. the subunits of nucleic acids are also the subunits of proteins.

What is the problem in this article? what solution does the article propose?