How do you know that energy and matter are conserved during the process of cellular respiration?

The nervous system interacts with the endocrine system by a. using hormones as connections b. sending nerve impulses directly to glands c. using neuroendocrine cells as connections d. sending neurotransmitters directly to neurons

Which would be the most useful source of evidence to support mcneill's contention?

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?