Lets say the plant that formed nodules is Species A, and the one who didn't is Species B.
If the nitrogen is concentrated in one area but at a low concentration, then Species A may have formed nodules because it is closer to the concentrated nitrogen. Species B didn't because the nitrogen that is active is being taken by Species A.
It has more than 1 atom involved.
Answer:
When the bladder is completely deflated, the fish has minimum volume and sinks to the ocean floor
2 abiotic(non living) limiting factors are water(A) and food(B)
