One of the many things plants do is produce oxygen through photosynthesis (which we use all the time)
Mitochondra, the organelle, responsible for the conversion of the chemical energy stored in food into ATP (adenosine triphosphate-energy rich molecule). The cell easily utilize these molecules and perform all of its functions
A placebo is kind of a "fake" treatment but, typically the person receiving a placebo is unaware it has no medical effect on them so they believe they are feeling better. For example, a lot of anxiety meds are placebos and people don't know so their brain tricks them into thinking they are feeling less anxious. This could be used in experiments where a group believes they are affected to see how they react
What experiment though lol
