Which of these cells of the dermal tissue of plants prevent water loss and control gas exchange?
a. phloem cells
b. companion cells
c. parenchyma cells
d. guard cells. user: when a plant grows as mediated by growth hormones, which main plant organs are at work

What happened to rosalind franklin in 1956?

Why would a drug the damages capsids treat a viral infection

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?