Question

Number of protofilaments in a microtubule is

• A. 10
• B. 13
• C. 16
• D. 18

Answer 1

The correct option is B 13

• A microtubule is a tubular linear polymer of tubulin protein which is a part of the cytoskeleton that helps to provide structure and shape to the cytoplasm of a eukaryotic cell.
  
• A single microtubule consists of 13 protofilaments (mammalian cell) and generally has 10-15 protofilaments.
• These protofilaments wind together to form a wide hollow cylinder of a diameter =24nm.
  
• So, the correct answer is '13'.