Question

In a centrosome, which structures serve as nucleation sites for the formation of

microtubules?
A. Tubulin protofilaments
B. alpha/beta-tubulin dimers
C. alpha tubulin monomers
D. gamma-tubulin rings

Answer 1

Gamma-tubulin rings in the centrosome serve as nucleation sites for the formation of microtubules, providing a template for the addition of alpha/beta-tubulin dimers.

Step-by-step explanation:

In a centrosome, the structures that serve as nucleation sites for the formation of microtubules are the gamma-tubulin rings.

Microtubules are composed of polymerized dimers of alpha-tubulin and beta-tubulin, which form the walls of these hollow cylinders.

However, the formation of microtubules begins at the gamma-tubulin rings located in the centrosomes.

These rings provide a template for the addition of alpha/beta-tubulin dimers and are crucial for the proper organization and orientation of the emerging microtubules during processes such as cell division.