Both glycogen and starch are polysaccharides of glucose units, formed by alpha(1-4) glycosidic linkages. Cellulose is also a glucose polysaccharide and makes the strong cell walls of plants. It is formed by glycosidic linkages of the opposite orientation, beta (1-4) instead of alpha(1-4). The former two are easily digestible, but the latter is not. Thinking about the overall structure of the two polysaccharides, can you devise an explanation as to why the former is easily digested and the latter not?

Which best compares habitat and niche? o niche is a place in which organisms live, and habitat is the way in which an organism fits into its habitat.o habitat is a place in which organisms live, and niche is the way in which an organism fits into its habitat.habitat is a group of organisms that live in an area, and niche is a specific species that lives in that areao niche is a group of organisms that live in an area, and habitat is a specific species that lives in that area.

Cells destroy body cells infected by a virus or bacteria.

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.