1. How do diffusion and facilitated diffusion differ? Diffusion favors one containment space over the other.
Diffusion does not require that the molecule be small enough to pass through the membrane.
Facilitated diffusion is affected by the concentration levels.
Facilitated diffusion requires the molecule to receive help to cross the cell membrane.

2. What does active transport require, and why does the process require it?
sodium and potassium; to pump out concentrated molecules
sodium; to replace the pumped out potassium
protein; to mark molecules that need to be forced out
energy; to move molecules against the concentration gradient

1) B not so sure

2) D very sure

Explanation:

2) Active transport require energy to move molecules against concentration gradient (during selective reabsorption in kidney)

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.

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.