Answer:
D. A hormonal signaling pathway between endocrine glands and tissues
Explanation:
Our body is formed by a complex organization of various tissue, organs and organ-systems. It has specific mechanisms to regulate the functions of all its cell, tissue and organs. Besides neural system, the endocrine system also plays a crucial role in the regulation of body functions. This system consists of many pathways that originate from the hormone secreting glands called endocrine glands and reaches to the target cell or tissue or organ. These pathways are collectively named as the endocrine axis.
The movement of substances (as by diffusion) across a cell membrane without the expenditure of energy.
They typically sleep about 16-17 hours a day; that’s a lot!
It would be a young puppy learns to beg for food by watching a older dog
