Agglutination of chromosomes is caused by a mitotic poison called

$DNA$ replication occurs in .........

Mitosis occurs in

Match the following columns and select the correct option:

Column-$I$	Column-$II$
$(1)$ $G_1$-phase	$(a)$ Interval between $DNA$ replication and $M$-phase
$(2)$ $G_2$-phase	$(b)$ Interval between $G_2$ and $G_1$ phase
$(3)$ $S$-phase	$(c)$ Interval between $M$ and $DNA$ replication
$(4)$ $M$-phase	$(d)$ Interval between the beginning and end of interphase

Which microscope is most suitable for studying the active stages of cell division?

Given below are two statements:
Statement $I$: During $G_0$ phase of cell cycle,the cell is metabolically inactive.
Statement $II$: The centrosome undergoes duplication during $S$ phase of interphase.
In the light of the above statements,choose the most appropriate answer from the options given below: