A student does an experiment using barium chloride and magnesium sulfate. The student adds 10.0 g of barium chloride with 5.8 g of magnesium sulfate in water. From the chemical reaction, 4.6 g of magnesium chloride are formed along with 11.2 g of barium sulfate as a solid. Why does this chemical reaction demonstrate the Law of Conservation of Mass? Please help me with this if you can Scie​

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?