Question

The solid linear cytoskeletal elements having a diameter of 6 nm and made up of a single type of monomer are known as

• A. Lamins
• B. Microfilaments
• C. Microtubules
• D. Intermediate filaments

Answer 1

The correct option is B

Microfilaments

The correct option is B.

Explanation of the correct option:

1. Eukaryotic cells are the only ones to have a cytoskeleton.
2. The cytoplasm is filled with a dynamic three-dimensional structure.
3. For mobility and stability, this structure serves as a skeleton and muscle at the same time.
4. The long fibers of the cytoskeleton are polymers of subunits.
5. The cytoskeleton is made up primarily of intermediate filaments, microfilaments, and microtubules.
6. The monomeric form of the protein is globular (G) actin monomers, and these two forms coexist in equilibrium in the cell.
7. Actin molecules that have been polymerized into double-stranded microfilaments.
8. A three-dimensional (3D) intracellular meshwork is created by the bundles of microfilaments.

Explanation of the incorrect options:

Option A:

1. The main structural proteins in the nucleus of an animal cell are called lamins.
2. The nuclear membrane's inside is lined with lamins, which offer a surface for the binding of proteins and chromatin as well as mechanical stability.

Option C:

1. The cytoskeleton's main building blocks are microtubules.
2. All eukaryotic cells contain them, and they play a role in mitosis, cell motility, intracellular transport, and cell shape preservation.
3. Alpha- and beta-tubulin subunits are organized into linear protofilaments to become microtubules.

Option D:

1. In the cells of many invertebrates, including vertebrates, intermediate filaments (IFs) are cytoskeletal structural elements.
2. Branchiostoma, a cephalochordate invertebrate, has been found to have homologs of the IF protein region of the intermediate filament tail.
3. The globular domain of lamin A/C is structured.

Final answer: The solid linear cytoskeletal elements having a diameter of 6 nm and made up of a single type of monomer are known as microfilaments.