<p>hopefully this thread can because used to discuss any questions in the blue book for SAT II biology that anyone is having trouble with and I'll start off</p>
<p>An ecologically sound reason for conserving tropical rain forests is that they</p>
<p>A. supply most of the oxygen that humans breathe
B. occupy four-fifths of Earth's surface
C. are the major producers of atmospheric nitrogen
D. are crucial to migratory ungulates like bison and wildebeest
E. are an important reservoir of biodiversity</p>
<p>I chose E but now that I look at it I can't help but wonder why D could not be a viable answer other than it's not true meaning that I thought for example that wildebeest live in the Serengeti not in tropical rain forests but assuming that it is true why can't it be a viable answer? I mean if bison or wildebeest went extinct due to the elimination of tropical rain forests then that would also decrease biodiversity because they are a food source for other predators, etc.</p>