Question

Function of centriole is
A. Formation of spindle fibres.
B. Formation of nucleolus.
C. Initiation of cell division.
D. Formation of cell plate.

Answer 1

Hint: The centrioles are minute submicroscopic sub-cylindrical structures which usually occur in pairs, inside a specialized cytoplasm known as the centrospheres or as kinoplasm.
The whole complex is known as the centrosome which is having two centrioles lying at right angles to each other.

Complete answer:
As the microtubule organizing center the centriole is an important event in the major cellular process that is cell division for the formation of spindle fibres and flagella formation.
The centrioles are essential for the formation of spindle fibres, which attach to the kinetochore discs present at the centromere and are therefore responsible for the movement of the chromatids during chromatid separation.
The pair of centriole duplicates within the cell and the two pairs migrate to the opposite ends of the cell to organize the mitotic spindle.

Therefore, the correct answer is option (A).

Additional information:
Each of the centrioles gives rise to a new centriole.
The centrioles that are newly formed remain tightly attached to the parent centriole, and it elongates during the S phase and also at G2 phase.
In the prophase stage the centriole pairs start moving towards the opposite sides of the cell, and also start forming the spindle simultaneously.
The migration and the positioning of the centrioles depend on the orientation of the spindle.
It also affects the chromosomes attachment to the spindle fibers.
The spindle fibers are responsible for the segregation of the chromosomes into the daughter cells.
When the cell cycle is formed, the cell contains two centrioles - one the mother centriole and the other newly formed centriole which is the daughter centriole.
After the segregation takes place, the centrioles determine the position of the nucleus and also affect the cellular organization in the new formed daughter cells.
The centrioles may be responsible for producing the flagella or cilia.

Note:
Without the centrioles, chromosomes would not be able to move during the formation of new cells.
The centrioles help to organize the assembly of the microtubules during the cell division.
In short the chromosomes use the centriole's microtubules as a highway during the process of cell division.