This is a slide of human cheek cells. after scraping the inside of their mouths, students in ms. gordon's class smeared the swab on a slide and stained them blue. these cells are parts of a large, complex organism, a human. but these cells. like the other cells in the human body all have an important organelle, seen here. it stains dark blue and is the control center of the cell. what is this organelle? a) dna b) cytoplasm c) membrane d) nucleus

i am 99% sure its D :)

Explanation:

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.