Answer:
I believe it's A and B
Explanation:
Hope my answer has helped you!
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.
The structure is D. a substrate
Afferent nerve fibers carry signals from the somatic receptors to the posterior horn of the spinal cord or to the brainstem. So i beleive it is 4 but not too sure. Hope this helped a bit (:
A vestigial organ, something that has yet to fall prey to evolution, but no longer serves a purpose, or the purpose it used to serve.
