Dr. Levitt is conducting a descriptive experiment where she is counting the numbers of chicks that hatch in one season for a particular species of bird. What is a major benefit of this experiment? A)The relationship does not show cause and effect.
B) It is repeatable.
C) The birds are unaware and unaffected by this study.
D) No relationships can be shown.

What food can provide the body with a quick source of the energy needed to carry out cell functions (a) whole grain bread (b) ground hamburger (c) vegetable oil (d) whole milk

Biology 1c cumulative exam i need awsners

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.