You are in the forest and see a large, snarling, drooling grizzly bear running directly toward you. The adrenaline rush you feel as you run toward the cabin is controlled by the sympathetic nervous system.
The sympathetic nervous system is a part of the autonomic nervous system which functions through various interconnected neurons. The sympathetic nervous system’s main role is to stimulate the neuronal and hormonal stress response (also known as body's fight-or-flight response). The sympathetic fibers in the adrenal medulla (inner part of the adrenal gland) produce acetylcholine (a neurotransmitter), which allow the high secretion of adrenaline and low amounts of noradrenaline from it. The sympathetic nervous system also prepares the body for action, especially in situations that are dangerous to survival.
The prokaryotes are unicellular organisms that lack organelles or other internal membrane-bound structures. Therefore, they do not have a nucleus, but, instead, generally have a single chromosome: a piece of circular, double-stranded DNA located in an area of the cell called a nucleoid
I think it's 90% but I am not sure.
It is a lipid. Lipids are some of the most complex basic materials in biology. You can remember them as they have 23 hydrogens, and one H0.
