The neurotransmitter in the body
which prepares it for "fight or flight" reaction is EPINEPHRINE. The
level of Epinephrine is remarkably high in patients who have anxiety-related
disorders. Also known as adrenalin or adrenaline, epinephrine is a hormone and at the same time a neurotransmitter; it is also used as medication.
Answer:
Active transport requires energy input from the cell.
2 is crescent and 4 is gibbous