Question

A microtubule is made of

• A. Protofilaments
• B. Microfilaments
• C. Microfibrils
• D. Elementary fibrils

Answer 1

The correct option is A Protofilaments

• 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.
  
• Protofilaments refer to a linear row of tubulin dimers that make up the microtubules.
• These tubulin dimers undergo polymerization to form the microtubules and it generally consists of 13 linear protofilaments which are wound together to form a hollow cylinder of 24nm.
  
• So, the correct answer is 'Protofilaments'.