You have an Elodea sprig in a test tube containing bromothymol blue. Then you watch it for several days. At what time of day will the oxygen level in the tube be the lowest?

If the birth rate of a population of dolphins is 2.0, the death rate is 0.5, and the population size is 100, what is this dolphin's population growth?

Why would a drug that damages capsids treat a viral infection? a. capsids prevent the lytic cycle from beginning. b. transduction requires a capsid. c. viruses use capsids to increase genetic variation. d. capsids provide protection for viruses.

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?