Question

The diameter of microtubule and microfilament is $25nm$ ad $7nm$ respectively. The intermediate filament will be

• A. $10-20nm$
• B. $8-10nm$
• C. $10-12nm$
• D. $5-7nm$

Answer 1

Answer: (A)

$10-20nm$

Intermediate filaments (IFs) are cytoskeletal components found in the cells of vertebrate animal species and perhaps also in other animals, fungi, plants, and unicellular organisms. They are composed of a family of related proteins sharing common structural and sequence features. Initially designated 'intermediate' because their average diameter (10 nm) is between those of narrower microfilaments (actin) and wider myosin filaments found in muscle cells, the diameter of intermediate filaments is now commonly compared to actin microfilaments (7 nm) and microtubules (25 nm).

So the correct option is '10-12 nm'.