What bacterias could we observe on school lockers?

Which class of molecules contains the amino group, nh2 (a) sugars (b) water (c) proteins (d) hydrocarbons

Consider the motion of the balloon and its air contents in terms of momentum. in step 1 above, the total momentum of the balloon and its contents was zero. recall that momentum = mv. both the balloon and the air inside it had a velocity of zero and therefore the total momentum was zero. now think about what happened when the air escaped from the balloon. a certain mass of air accelerated in one direction. in order to keep the total momentum of the system zero, the balloon itself (which has mass) had to accelerate in the opposite direction. use this scenario to you explain why the soda can rotates when the water squirts out of the escape holes. what was your hypothesis concerning the water-filled can? according to your data, do you think your hypothesis was correct? (be sure to refer to your data when answering this question.) summarize any difficulties or problems you had in performing the experiment that might have affected the results. describe how you might change the procedure to avoid these problems. give at least one more example of newton's third law in everyday life.

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.