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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Involuntary contraction of a single motor unit is known as
assistant
The correct answer is  Fasciculation : It is involuntary contraction of a single motor unit. It is visible grossly.
Fibrillation : It is spontaneous, repititive contraction of a single muscle fibre. It is not visible grossly.