Who divided the cell cycle into four phases (i.e., $G_1$, $S$, $G_2$, and $M$)?

During the $G_2$-phase of the cell cycle,the amount of $DNA$ in the chromosomes is .......

Which of the following statements are correct for $G_{1}$-phase?
$I.$ It is the last substage of interphase
$II.$ Cell organelles do not increase in number
$III.$ Cell grows in size and content both
$IV.$ It synthesizes $RNAs$,proteins and other biochemicals for cell growth and subsequent replication of $DNA$
Choose the correct option

What is continuously occurring in the cell during $G_1$,$S$,and $G_2$ phases?

Describe the events taking place during interphase.

In the somatic cell cycle: