Can you add the picture or describe it to me? Right now I'd guess that it's probably bacteria because bacteria breaks it down into ammonium and nitrate, which is taken up by the plants by a process of nitrogen fixation. So, D.
Four single bonds, 2- two single and one double bond, 3- one single and one triple bond, 4- two double bonds.
Hey there! Cellular membrane and cell wall is your answer.
As you increase exercise and muscle activity, your heart rates increases. That is one feedback mechanism. Your heart delivers oxygen and nutrients to your muscle and other parts of the body quicker.
