18)Healthy ecosystems cycle matter.

A)Draw a diagram to illustrate or describe in words the cycle(s) of matter within the healthy lake in Model 1.

B) How did the influx of nutrients in the lake disrupt the cycle of matter in the lake and cause eutrophication?

19A)Draw a diagram to illustrate or describe in words the flow of energy through the healthy lake in Model 1.

19B)How did the influx of nutrients in the lake disrupt the flow of energy in the lake and cause eutrophication?

How many major plates cover the earth

What type of competition exsist between two species. turtles and fish

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?