Which statement describes an effect that humans have on the geosphere when they build a dam? ice may form on the lake. plants may grow on the dam. rocks and minerals are used to build the dam. water from the lake may evaporate into the air.

Which of the following will not cause mass extinction? a. drastic change is weather b. geological change c. both a and b d. none of the above

The united states produces an average of 429 billion pounds of food annually. about 133 billion pounds of that food ends up as waste.the percentage of food that the united states wastes each year is %.

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?