a because the marble changed its position quickly meaning that it was in motion
Answer: Nerve cell
Cells of the nervous system, called nerve cells or neurons, are specialized to carry "messages" through an electrochemical process.
Answer:
False
Explanation:
Scientist believe that the primitive atmosphere lacked free oxygen. Oxygen is a highly reactive molecule that would have made difficult for complex macromolecules to appear and then create life. Rocks from the precambrian period support this theory.
Anaerobic cells appeared first, then photosynthesis appeared filling the atmosphere with oxygen and the aerobic organism develop cellular respiration to obtain energy, a process more efficient than anaerobic respiration.
Explanation:
It sends message directly to muscles and glands