How does the energy produced in the sun's core reach the sun's outer surface? O A It moves slowly through the radiation zone as electromagnetic radiation, and then through the convection zone as a loop of hot gasses
that rise before they cool and sink,
OB. It moves through the convection zone as a loop of hot gasses that rise before they cool and sink, and then as electromagnetic radiation
moving slowly through the radiation zone.
OC. It moves slowly through the core as electromagnetic radiation, and then through the convection zone as a loop of hot gasses that rise
before they cool and sink.
OD. It moves through the convection zone as a loop of hot gasses that rise before they cool and sink, and then as electromagnetic radiation
moving slowly through the core.

Which would happen if more forests were cut down? a. the nitrogen cycle would be stopped b. nitrogen would be fixed by bacteria more quickly c. the amount of co2 in the atmosphere would increase d. fossil fuels would build up in the soil c the amount of co2 in the atmosphere would increase

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.

Which term describes a normal value for something in the body? a. homeostasis b. set point c. feedback loop d. integration center