What does the nucleus consist of

If you are talking about atomic nucleus then it's consist of protons and neutrons.

Explanation:

But if you're talking about cell nucleus

Then,

It contains nuclear envelope, nuclear lamina, nucleolus, chromosomes, nucleoplasm .

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.