secondary succesion takes place
Answer:
D
Explanation:
There are many food chains within a food web, so D seems like the best possible answer :)
The process which occurs in the structures that are labeled X is Kreb's cycle.
It has to do with releasing stored energy in the form of adenosine triphosphate (ATP). This is an extremely important part of metabolism and was first introduced by Hans Adolf Krebs in 1937.
Biology is the study of living thing
