The effect of high levels of adp is to
increase the activity of the enzyme
decrease the activity of the enzyme
have no effect on the activity of the enzyme
slow down the pathway

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link:

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs