During which phase are chromosomes referred to as chromatin?

Some dividing cells exit the cell cycle and enter a vegetative,inactive stage called the quiescent stage $(G_{0})$. This process occurs at the end of:

In which phase does $DNA$ replication occur?

$A$ biosynthetic phase where cell organelles duplicate themselves is:

During which phase of interphase do biosynthetic processes occur?

The number of chromosomes in $G_1$ phase is $36$. What is the number of chromosomes in $S$ phase?