<span>Norepinephrine uses the Second
Messenger System, which means, cells signal to each other what molecules have
been released that will trigger a physiological reaction. </span>
<span>
This phenomenon is activated after the ligand (ion or molecule) is bonded to its receptor
(protein molecule), creating a variation that causes a chain-reaction, that will
finally activate the Second Messenger. The latter will activate intercellular
molecules that will be able to control the cell’s activity. </span>
Convergent plate boundaries
Answer:
If I where to guess I would say b and c.
sorry if its not correct
Explanation:
I disagree with the current answer. I believe the answer is the one you have selected. This is because the three domains of life are separated into 3 categories, bacteria, archeabacteria, and eukaryotes. Archeabacteria are prokaryotic, and possess no true nucleus.
