Answer:
B. method by which neurons communicate
Blue (right) is deoxygenated and Red (left) is oxygenated.
think of it as like a cartoon when a character cant breathe, they turn purple or blue. While in real life, deoxygenated blood is not actually blue and it is a deep red and the oxygenated blood is bright red. They just show it as blue to help you differentiate.
yes, because we cannot see DNA without a machine, and its the same with nano-molecules, that are blind to the human eye
