The solid linear cytoskeletal elements having a diameter of 6 nm and made up of a single type of monomer are known as (a) microtubules (b) microfilaments (c) intermediate filaments (d) lamins.
Option B is correct answer. Microtubules are hollow microscopic tubular structures with an external diameter of 24 nm and of variable length. They are composed of tubulin. Intermediate filaments are the numerous microscopic protein fibres of about 10 nm thickness that form part of the cytoskeleton. They are made up of a variety of proteins e.g. keratin in nails.
