Which system is responsible for the chemical control and coordination of our body?

Consider the following statements about insulin:
$I$. Human insulin is made up of $51$ amino acids arranged in two polypeptide chains.
$II$. The two polypeptide chains are interconnected by two disulphide bridges.
$III$. In mammals,including humans,insulin is synthesized as a pro-hormone,which contains an extra stretch called the $C$-peptide.
$IV$. $C$-peptide is not present in the mature insulin.
Which of the statements given above are correct?

Body coordination is exhibited by

From the perspective of embryonic origin,which of the following is ectodermal?

Complete the following analogy-based questions:
$1$. Juxtaglomerular cells of kidney : Erythropoietin :: Atrial wall of heart : .....
$2$. Follicle : Estrogen :: Corpus luteum : .....
$3$. Decrease in glucose utilization at cellular level : Hyperglycemia :: Decrease in blood glucose level : .....
$4$. $\alpha$-cells of pancreas : Glucagon :: $\beta$-cells of pancreas : .....

All functions of the body are regulated and integrated by