Question

What is the role of microfilaments in cell division?

Answer 1

Hint: Microtubules are polymers of tubulin. Microtubules form an important part of the cytoskeleton. Microtubules provide structure, resistance and shape to an eukaryotic cell.

Complete answer:
The centrosomes are the main microtubule organizing centers of a cell. They come into play during mitosis. A centrosome is made of two tubular and cylindrical structures called centrioles. A centriole is made up of nine microtubules with a pair of partial microtubules attached to each main microtubule. The centrosome plays an important function of maintaining the polarity of the microtubules during mitosis.
There are three classes of microtubules, namely:
- Astral microtubules
- Interpolar or polar microtubules
- Kinetochore microtubules
Astral microtubules only exist during mitosis. They develop from the centrosome but face no interaction with the chromosomes or other microtubules developing from other microtubules. The astral microtubules help the centrosomes position themselves away from each other in the cell during mitosis. The astral microtubules never interact with the mitotic spindle.
Interpolar microtubules also radiate out of the centrosome during mitosis. Interpolar microtubules radiate themselves and interact with the mitotic spindle.
Kinetochore microtubules develop direct connections with the kinetochores of the cell during mitosis. The kinetochores are located in the mitotic spindle.

Note:
Microtubules are formed with the polymerization of alpha and beta tubulin into protofilaments that eventually associate to form a microtubule. Alpha and beta tubulin are globular proteins.
Microtubules form the internal structure of cilia and flagella. Microtubules are major components of mitotic spindles. They are used to pull the chromosomes apart.