Question

Cell Division is initiated by
(a) Centrosome
(b) Centriole
(c) Centromeme
(d) Chromomere

Answer 1

Hint: Cell division is initiated by two, barrel-shaped clusters of microtubules. They are organelles serving as the main microtubule organizing centers of the cell.
Mitosis is the process of division of the eukaryotic nucleus where a parent cell divides to form two identical daughter cells.

Complete answer:
Cell division is initiated by centrosomes.
Prophase is the initial phase of mitosis. It is the longest phase of mitosis.
The centrosome replicates in the S phase of interphase. The S phase or the Synthesis phase is the phase of the cell cycle that occurs between the ${G}_{1}$ and ${G}_{2}$ phases.
The centrosome only replicates once per cycle in interphase thus a bipolar mitotic spindle axis is ensured. The replication of the single centrosome is initiated at the transition between ${G}_{1}$ and S phase. This replication is completed before mitosis.
The duplicated centrosomes play a major role at the organization of the poles of the mitotic spindle.

So, the correct answer is ‘Centromere’.

Note:
Centriole duplication is such that the paired centriole splits and a new centriole associates with each half creating two centrosomes.
The cell possesses a 4N DNA content by the end of ${G}_{2}$.
The interphase of eukaryotic cell division has three main phases. They are:
-${G}_{1}$
-S
${G}_{2}$
During the ${G}_{1}$ phase, special cellular functions of the cell occur which prepare the cell for DNA replication. There is a checkpoint between the ${G}_{1}$ and S phase which checks for cell size and DNA damage.
During the S phase, the chromosomes are replicated to maintain the genetic content.
During the ${G}_{2}$ phase, the cell grows for the final time.