This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Physiology
[{'content': 'Which of the following ion plays a role in exocytosis? \nSelect and explain. \nA. Sodium, B. Potassium, C. Calcium, D. Magnesium', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C CalciumRef: Ganong 25th edition, P 46* Exocytosis is a calcium dependent process where vesicles containing material for export are targeted to the cell membrane.* This area of fusion then breaks down leaving the contents of vesicle outside the cell membrane intact.* The reverse of exocytosis is called as endocytosis and is mediated by the protein Clathrin.', 'role': 'assistant'}]