Which molecules may diffuse across a cell membrane without the expenditure of energy or the use of membrane proteins?

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?

Which component in a graph indicates an independent factor? a. y-axis b. x-axis c. scale

Astore manager timed janette to see how long it would take her to fold and put away a sweater, a shirt, a pair of pants, and a scarf. it took her 26.1 seconds for the shirt, 24.3 seconds for the sweater, 32.8 seconds for the pants, and 18.2 seconds for the scarf. what was the average time it took janette to fold and put away all four items? during a catered lunch, an average of 4 cups of tea are poured per minute. the lunch will last 2 hours. how many gallons of tea should the caterer bring if there are 16 cups in one gallon?