14. L.15.8 The table below summarizes the ideas and findings of scientists Scientist(s) Alexander Oparin Miller and Urey Contribution Hypothesized early life may have been formed in high heat environments, such as the sun or lightning strikes. Observed that gasses such as methane, ammonia, and hydrogen gasses react to produce amino acids when exposed to temperature fluctuations and electricity. Found that adding heat to solutions of amino acids produces primitive "protocells" Sidney Fox How does the work of these scientists contribute to the study of Biology?​

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?