Is the layer of the atmosphere where particles of air can escape into space

a troposphere
b stratosphere
c mesosphere
d exosphere

the is directly above the troposphere

a stratosphere
b mesosphere
c exosphere
d troposphere

me with these two you

Select all the correct answers. lactobacillus is a bacteria that live inside humans. these bacteria live on the nutrients from our bodies. they to keep our gut clean and healthy. s. typhi is a bacteria that enter our bodies through contaminated food. this bacteria causes infections in the body. based on this information, which two statements about the association between these bacteria and humans are true? a. lactobacillus shares a parasitic relationship with humans. b. s .typhi shares a parasitic relationship with humans. c. both lactobacillus and s. typhi share a parasitic relationship with humans. d. both lactobacillus and s. typhi share a mutualistic relationship with humans. e. lactobacillus shares a mutualistic relationship with humans, and s. typhi shares a parasitic relationship multiply chrse

In a cladogram' when does a group of organisms branch off

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.