Many of the biochemical reactions that occur within cells are catalyzed by enzymes. which of the following statements is true about most enzyme-assisted reactions? > most enzyme-assisted reactions are slow.> most enzyme-assisted reactions can take place at any temperature. > most enzyme-assisted reactions can take place only within a ribosome. > most enzyme-assisted reactions are reversible.

Which of the following statements is true? a. there are more chromosomes in an organism than there are genes. b. there are more genes in an organism that there are chemical bases. c. dna is made of sugar, phosphate, and carbon. d. genes are found in specific locations on a chromosome.

Which organelles are labeled d, and what is one feature that distinguishes them from the other labeled organelles chloroplasts the only organelles that produce sugars from sunlight mosomes, only found in animal and bacterial cells centricles only found in animal cells mitochondra, the only energo-generating structures found in cells

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.