What diagram ? I don't see one
Answer: few animals can undergo both.
brain is the organ which does play a role in mechanical or chemical digestion
Answer:
Yes.
Explanation:
Yes, a tree is falling over in a forest make a sound because both the tree and ground are hard surfaces which can produces sound by contact physically with each other. For testing this hypothesis, we have to take a tree and cut that tree. when the tree falls on the ground it will definitely produces sounds by contact physically with the ground when falls with a large force.