Intermediate filaments are Intermediate filaments are differ

Intermediate filaments are Intermediate filaments are...

different in different cell types.

composed of tubulin.

composed of globular proteins only.

smaller than actin filaments.

None of these are correct.

Solution

Answer 1 is correct.

Intermediate filaments are...different in different cell types.

Intermediate filaments (IFs) are cytoskeletal components with average diameter of 10 nm, which is between those of narrower microfilaments (actin) and wider myosin filaments found in muscle cells. IFs are the only components of the cytoskeleton comprised of polymerized, fibrous protein subunits in contrast to the globular chain subunits of microfilaments and microtubules.

IFs are of many different types found in different cells, in general all are polymers. Type I and type II comprise of acidic and basic keratins and are present in epithelial cells of hair, nails, horns, scales etc. Type III comprise of Desmins found in muscle cells, GFAP found in astrocytes and glia, pripherin found in peripheral neurons, Vimetin found in  fibroblasts, leukocytes, and blood vessel endothelial cells. Also there are various types of type IV IF; Type V IFs are lamins found in nucleus and type VI is Nestin.