How does a good experimental conclusion differ from an inference?

What are the formed elements (cell or parts of cell) in blood and what are their functions ?

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

What are examples of the plant life and animal life that can be found in each type of terrarium