Do you think Macbeth is really seeing Banquo's
ghost, or is it just his imagination?

It’s his imagination. this is the point in the story where macbeth is starting to experience paranoia (and almost insanity). banquo’s “ghost” is a creation from macbeth’s conscience that is sending a message that macbeth maybe shouldn’t have killed him.

It takes place in the mitochondria.in three stages: glycolysis, krebs cycle, and electron transport.