The local mediator nitric oxide stimulates the intracellular enzyme guanylyl cyclase by . Group of answer choices A) diffusing into cells and stimulating the cyclase directly. B) activating a G protein. C) activating a receptor tyrosine kinase. D) activating an intracellular protein kinase. E) none of the above.

Plants that have reproductive structures called cones are?

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?

Identify any four organelles that should be present in the eukaryotic organism and describe the function of each organelle