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.
Here's a chart. Not sure what your choices are though.
B) it's easier to see the cellular parts such as the nucleus. For A) I'm inferencing this way the cover doesn't get smudge by the eraser
Answer:
Diffusion is the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration. For cell transport, diffusion is the movement of small molecules across the cell membrane. ... The kinetic energy of the molecules results in random motion, causing diffusion.
