1. As a supervisor in the infection-control unit, you hire a local microbiologist to analyze samples from your hospital's hot-water tank for microbial contamination Although
she was unable to culture any microbes,
she reports that basic microscopic analysis
revealed the presence of cells 0.8 um in diameter that lacked a nucleus.
Transmission electron microscopy showed that the cells lacked membrane-bound
organelles but did contain ribosomes. Which domain of life do you hypothesize
these cells represent? Discuss any additional analysis that could be performed to
determine this classification most accurately.

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?