(a)

How does chemical coordination take place in human beings?

• Chemical coordination in human beings take place through the endocrine system by the secretion of hormones from the endocrine glands.

• Hormones are chemical messenger secreted by the glands in the blood that reach different parts of the body and bring specific changes to particular organs.

• The organs which they affect are called target organs. The hormones control and coordinate various functions of the animal body like growth and development, metabolism, secondary sexual characteristics.