Plant and animals cells are very similar structurally, though some differences do exist. the vacuole is one organelle that differs in plant and animal cells. which statement best elaborates on the reason for this difference? a) vacuoles plants make their own food by converting light energy, animals do not make their own food. b) animal cells have large vacuoles to remove waste, while plant cells do not produce waste and have small vacuoles. c) vacuoles are much larger in plant cells than in animal cells, because they tend to hold more water to stay upright. d) vacuoles in animal cells are porous, so oxygen can pass, while those in plant cells have solid walls to keep water inside.

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 description provides the best objective summary of the article in the passage?

How water is moving through the ecosystem ?