Which sentences correctly characterize seagrass? seagrasses are very tall and can grow several feet a day. they act as habitats for many marine species. they generate up to 10 liters of carbon a day and add nutrients to the sea. they are a source of food for manatees and other herbivores. they are toxic to bacteria and algae and protect other organisms by inhibiting the growth of microorganisms. creatures that reside in seagrass meadows are not of commercial use to humans.

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?