. Which comparison of ecosystems is true? A. Tundras are warmer than grasslands.
B. Grasslands get more rain than deserts.
C. Deserts have more plants than rainforests.
D. Rainforests are rockier than tundras.

B

Explanation:

Because grasslands usually get around 500 to 950 mm of rain while deserts usually get around less than 300 mm of rain

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.