Part II: Read the text below, and then answer the questions. Corals, the basic structures of coral reefs, are affected by the increasing acidity (decreasing pH) of the oceans. When the ocean absorbs carbon dioxide, the carbon dioxide reacts with water and other substances to form carbonic acid. This process uses substances in the ocean that corals use to build their skeletons. So, the more carbon dioxide there is in the ocean, the harder it is for corals to build their skeletons. Ocean acidification can also destroy existing coral reefs.

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

How does friction with the atmosphere affect the speed of an artificial satellite

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.