Author Question: Which hormone helps establish day-night cycles? A) Melatonin B) Dopamine C) Thyroxine D) ... (Read 27 times)

Jipu 123 · **on:** Jul 3, 2018

Which hormone helps establish day-night cycles?

A) Melatonin B) Dopamine C) Thyroxine D) Norepinephrine

Question 2

The relatively diffuse collection of phagocytic cells throughout the body is called what?

A) Monocyte-macrophage system B) Reticuloendothelial system
C) Phagocytic system D) Both A and B