These are known as Hormones. Hormones are chemical messengers that are released in one tissue normally endocrine glands for example, adrenal glands, pituitary glands, and transported in the blood stream to alter the activities of specific cells in other tissues. Hormones serves as messengers, controlling and coordinating activities or processes such as growth, metabolism and fertility in the body.
Cell, Tissue, Organ, Organ System
(Hope this Helps)
Explanation:
They will be combine together and form a large same land as before some thousand years ago. This will somehow destroy the then population but will start a new civilization with new innovations and ammenities.
