An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to .

(A) make life on land difficult for aerobic organisms.
(B) change the atmosphere from oxidizing to reducing.
(C) make it easier to maintain reduced molecules.
(D) cause iron in ocean water and terrestrial rocks to rust (oxidize).
(E) prevent the formation of an ozone layer.

Actual age your first developed of age well comparison age refers to absolute age true or false

Monitor and apply fix up strategies

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?